Ever since I got my N900 back in December I've had occasional problems with the screen being unresponsive for 10 to 20 seconds when I wake it up, on incoming phone calls or when an alarm sounds. I've been searching this forum for other people having this same problem but I've had no luck so far.

In an attempt to fix the problem I re-flashed the phone with the USA version of code only to have my T-Mobile SIM card quit being recognized. At this point I sent an email to Nokia about my problems and mentioned that I had re-flashed my phone trying to fix the unresponsive screen problem and that had stopped my SIM card from being recognized. After four days I was told by Nokia that I had voided my warranty by re-flashing my phone but that I could pay for them to fix it.

This seems really strange to me because Nokia makes available the phone re-flasher tool (in Linux, Windows, and Mac versions), all of the various versions of the phone software (USA, Europe, Global, Etc.), and the file to wipe the internal flash that holds the file system. Eventually I found a thread on this forum about using the newest version of the "Global" version of the phone software to restore the ability of the phone to recognize the T-Mobile SIM card.

Using that file I now have the phone working again with the T-Mobile SIM card but I still have the problem with the phone's screen sometimes being unresponsive after it wakes up on an incoming phone call or an alarm goes off or when I wake up the phone. If I use the button at the top of the phone to wake the phone then the unlock slider is frozen. If I use the side button to power up the phone then the entire screen is frozen. After the ten to twenty second delay the slider works again or the screen recovers and starts allowing me to use the stylus. I would say this screen freezing happens about every three calls out of fifteen calls (or wake ups). On incoming calls I am hitting the green "Answer" button hard enough to discolor the display from pressure and the phone never answers the call so I know the problem is not that I am using too little pressure on the green answer button.

Eventually the incoming call either gets answered by voice mail or the caller hangs up. At that time I can immediately call the person back and the phone works normally, with the screen again responding to all of the normal button pushes.

This problem has been driving me crazy for two months now. And Nokia, instead of offering to fix the phone, just tells me that I've voided my warranty by re-flashing my phone. I'd sell this thing on eBay and buy a Nexus One but I can't sell anyone a phone that has a known problem. Does anyone out there have a fix for this problem? I suspect that it has to do with the interrupt priority of the touch screen or something similar. I'd ask Nokia for help but they seem to be useless and probably clueless. This is my fourth and at this point last Nokia phone.
-- Don

didn't know that reflashing voids the warranty. o.O

did you flash your emmc too? or only your device?

I re-flashed both but the Nokia email didn't differentiate. Here is part of their email:

"Based on your concern, we regret to inform you that since you have flashed your N900, this voids your warranty priviledges. It is repairable but unfrotunately fees would be applied. If you decide to go through with the repair, you would need to go to your nearest NCP (Nokia Care Point) for further instructions."

This email was sent in response to my email about the SIM card becoming unrecognized after I flashed my phone to try to fix the problem with the phone being unresponsive upon wake-up or during incoming phone calls or alarms. As I said in my earlier email, I was able to get the SIM card working again but I still have the screen freezing problem.
-- Don

I have just started to have this happen to my phone too... It's been fine before, but now when waking up (from dark screen, or lock etc), it takes about 5 seconds or so before it registers my touch...

Any solutions to this?

MeeGo

How does that help with my N900?

im pretty sure this is a well known issue, its been affecting mine since day 1 that i got it, on receiving a call mainly. it flips from landscape to portrait and back, sometime the answer button works sometimes not.

having thinks like microb open while the phone is dark can cause issues i find because as soon as you wake it up the web, widgets and any other web connection on that screen or in background trys to refresh

No fix best i know, i regulary run OptimizeN900 script though to keep it running smooth

I'll have to check that out, thanks for the tip...

I've not changed anything recently, it's always been fine. No new widgets or anything...

messing with transitions.ini might help ("might" as in "i think perhaps there is a chance")

it's indeed quite annoying how bogged down the device gets when switching from portrait to landscape and vice-versa; i have the impression it might be in part due to all programs in the backgrounf being switched together with the program that has focus (i think what it is doing is more than rotating and rearranging GUI elements, it seems it changes the screen resolution itself and then renders the result at 90 degrees (or is that 270?) at the OS level, like how you can do in desktop machines)

its been getting worse here too, im so frustrated.

any ideas?