What about v49, that is the latest one right?

Sorry, just seeing this. I have a nice thread on some of the fun tweaks and toys available for the N900. Lots of info, some of it's a little old, but a good place for a "noob" to start.

The best kernel right now I'd say is either K46 (the last Titan kernel) or K48 (the last stable Pali kernel). K49 is nice, but it's still got a few glitches going on. K46 is rock solid, and far better than the stock Nokia kernel. K48 has lots of new tweaks, much better integration with h.e.n. and CSSU, and is relatively solid.

The only down-side of K48 vs K46 I've seen is that it does change something in the power management, so that some devices that used to run on the ultra-low voltage profiles no longer are stable with them. Frankly, I'd steer clear of trying to do excessive under-voltage anyway. The minor power savings doesn't seem worth the instability and the chance of data corruption on the device.

PS: I love that you're showing how this place should work. Lots of newbies come here demanding support or being rude. Most wind up getting very little because of their attitude. You came in asking politely and got tons of help rather quickly. It helps that you're clearly searching for info on your own too. Also, don't forget to thank people that help you! (Thanks button is lower right of each post!)

Thank you all for your help and advices.
Right now i am trying to flash emmc again becase something went wrong whn i repartitioned it and now i have 18.99 gb in my docs, and 78 mb memory for installable applications. The problem is that when i try to flash i get this now:

"C:\Program Files\maemo\flasher-3.5>
C:\Program Files\maemo\flasher-3.5>flasher-3.5.exe -F RX-51_2009SE_10.2010.13-2.
VANILLA_PR_EMMC_MR0_ARM.bin -f
flasher v2.5.2 (Sep 24 2009)

Image 'mmc', size 255947 kB
Version RX-51_2009SE_10.2010.13-2.VANILLA
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_20.2010.36-2_PR_MR0
Booting device into flash mode.
Suitable USB device not found, waiting."

Why cannot i flash vanilla anymore?
I keep getting the above error message

Yea it is the latest one but it is not quiet stable yet

I never mentioned NEW CPU, I think you misread me

There's no right way and wrong way to overclocking the device, you may ultimately shorten the lifespan of the said device when the CPU is running at a new higher frequency range than what it was.

A little help here maybe.
I still cannot flash emmc it gives me the mentioned error.
Is there any xterm command to format or restore original partitions?

whew, I managed to flash it with vanilla, and get everything back to normal (the problem was with my computer, so i go to my second computer and done it).

5his was scarry (i was afraid i will remain with 77mb for applications), but i'm not giving up. i will try another method to increase applications memory.

Done.
I increaseded app memory following this instructions http://forum.lowyat.net/topic/1652293/+1587
Now i have 9.04 gb available app memory, and 17.96 gb available in my docs.
currently i'm working on getting android on internal emmc

I thought that the device came underclocked from the manufacturer. The 3530 (am I right?) can be clocked up to 800Mhz and when I got my N900 (PR1.0 era) it had a max of 550.