Similar tragedy here! Last saturday I just left it to die without battery.. As Sunday came on.. no sim at all!
Many reflashs later (with different fws), not much has changed. (It "worked" for less than 5 mins this morning after reflashing with the global (2.2009.51-1). Now I just reflashed again and am trying to do ALL the updates from scratch!

But yes... picture a pissed off fella, that me now!
I'll report if I have news.
PS: despite this post being totally NOT informative, I feel like it may help someone in the same situation to feel a little less "alone".

I may NOT know what I am talking, as usual

Take out the sim card and re-insert, setting>menu (top border) > Restore original settings. Does that work?

bun

so there are other people with the same problems, but i have it from the beginning!
with all the 3 firmwares we have had now.

what happend to me is that now and then the N900 looses its simcard (when it was just being used).
Sometimes it asks for a pincode right away, sometimes i have to reboot, but other times a reboot wasnt enough i really have to take out the battery and sim and reinsert it.

But now 3 times that wasnt even enough and it wouldnt do its job then, 2 times after 1 or 2 nights without battery i could get it working again. But it seems that the 3th time where i am in now (typing this on the N900 with no sim) is the 'real' thing and i cant get my simcard to work.

it works fine in my old phone the E90 but as explained above the N900 just boots up which takes very very long and then just doesnt find my sim. hopefully this stays now this way when i go to a repair shop..

i thought i try to reflash my phone completely with flasher35

But even that doesnt work (i am on Windows 7 64 bit where flasher doesnt seem to work at all on because of driver signing issues i think, which annoys me even more because currently thats the most sold OS there is and tooling doesnt work!)

I am on Ultimate and have Virtual PC 7 installed so by holding the U when i attach the usb and then take over the usb in the virtual pc i get flasher to recognize the N900 in update mode, so far so good but then:

C:\Program Files\maemo\flasher-3.5>flasher-3.5.exe -F RX-51_2009SE_3.2010.02-8_P
R_COMBINED_MR0_ARM.bin -f -R
flasher v2.5.2 (Sep 24 2009)

SW version in image: RX-51_2009SE_3.2010.02-8_PR_MR0
Image 'kernel', size 1704 kB
Version 2.6.28-20094803.3+0m5
Image 'rootfs', size 158336 kB
Version RX-51_2009SE_3.2010.02-8_PR_MR0
Image 'cmt-2nd', size 81408 bytes
Version BB5_09.36
Image 'cmt-algo', size 519808 bytes
Version BB5_09.36
Image 'cmt-mcusw', size 5824 kB
Version rx51_ICPR82_09w47
Image '2nd', size 14720 bytes
Valid for RX-51: 2217, 2218, 2219, 2220, 2120
Version 1.4.14.4.4+0m5
Image 'xloader', size 14848 bytes
Valid for RX-51: 2217, 2218, 2219, 2220, 2120
Version 1.4.14.4.4+0m5
Image 'secondary', size 109440 bytes
Valid for RX-51: 2217, 2218, 2219, 2220, 2120
Version 1.4.14.4.4+0m5
Image '2nd', size 14720 bytes
Valid for RX-51: 2101, 2102, 2103
Version 1.4.14.4.4+0m5
Image 'xloader', size 14848 bytes
Valid for RX-51: 2101, 2102, 2103
Version 1.4.14.4.4+0m5
Image 'secondary', size 109440 bytes
Valid for RX-51: 2101, 2102, 2103
Version 1.4.14.4.4+0m5
Image '2nd', size 14720 bytes
Valid for RX-51: 2104, 2105, 2106, 2107, 2108, 2109, 2110, 2111, 2112, 2
113, 2114, 2115, 2116, 2117, 2118, 2119
Version 1.4.14.4.4+0m5
Image 'xloader', size 14848 bytes
Valid for RX-51: 2104, 2105, 2106, 2107, 2108, 2109, 2110, 2111, 2112, 2
113, 2114, 2115, 2116, 2117, 2118, 2119
Version 1.4.14.4.4+0m5
Image 'secondary', size 109440 bytes
Valid for RX-51: 2104, 2105, 2106, 2107, 2108, 2109, 2110, 2111, 2112, 2
113, 2114, 2115, 2116, 2117, 2118, 2119
Version 1.4.14.4.4+0m5
Image '2nd', size 14720 bytes
Valid for RX-51: 2201, 2202, 2203, 2204, 2205, 2206, 2207, 2208, 2209, 2
210, 2211, 2212, 2213, 2214, 2215, 2216
Version 1.4.14.4.4+0m5
Image 'xloader', size 14848 bytes
Valid for RX-51: 2201, 2202, 2203, 2204, 2205, 2206, 2207, 2208, 2209, 2
210, 2211, 2212, 2213, 2214, 2215, 2216
Version 1.4.14.4.4+0m5
Image 'secondary', size 109440 bytes
Valid for RX-51: 2201, 2202, 2203, 2204, 2205, 2206, 2207, 2208, 2209, 2
210, 2211, 2212, 2213, 2214, 2215, 2216
Version 1.4.14.4.4+0m5
USB device found found at bus bus-0, device address \\.\libusb0-0001--0x0421-0x0
105.
Found device RX-51, hardware revision 2101
NOLO version 1.4.14
Version of 'sw-release': RX-51_2009SE_3.2010.02-8_PR_MR0
Sending xloader image (14 kB)...
100% (14 of 0 kB, avg. 14 kB/s)
Sending secondary image (106 kB)...
100% (106 of 0 kB, avg. 106 kB/s)
Flashing bootloader... done.
Sending cmt-2nd image (79 kB)...
100% (79 of 0 kB, avg. 79 kB/s)
Sending cmt-algo image (507 kB)...
100% (507 of 0 kB, avg. 507 kB/s)
Sending cmt-mcusw image (5824 kB)...
100% (5824 of 0 kB, avg. 5824 kB/s)
Flashing cmt-mcusw... Sending request 0x50 failed: No error

so even that doesnt work for me...

If you hold F8 when you boot your PC you have the option to disable driver signatures, try that...all I can suggest.

Try using a 32 bit OS, thankfully the bootloader was flashed, otherwise you would've needed to take it to Nokia.

you made a downgrade! Be shure that you have the last firmware, or...change firmware country.... an then reflash it again...

i didnt make a downgrade, how could i do that?

"3.2010.02-8" thats the latest firmware there is, P1.2 is still not there!

But as i said i have hatd these sim card not recognized problems from the start (dec 2009) only then not that often and mostly fixed by a reboot, now it seems it is really broken. So i think it is hardware anyway, i brought mine today to a Nokia Care Center and they will mail it to nokia, just now in a different waiting game then before.. Now on my N900 to return else waiting for 1.2....

ok... reflash the vanilla image, the 1st image of maemo, the 2nd image of maemo, end then the last one the PR 1.1 i mean... if you need help commonwarrior@hotmail.it MSN i'm online

people i have been facing this problem since quite some time now. it some how gets triggered each time i attempt to connect my phone to the GPRS. i have no idea why this is getting triggered this way but i would be interested in knowing if there is a pattern here. are any of you also finding that the sim card gets derecognised when you connect to the GPRS?