recently, i found my N810 often enters to a state that it doesn't repond to either touch events on the system or the switch keys.later i found one trick to make it reponse again by pushing the power button, then the original issued key will firstly reponds, then the shutdown menu, it's quite annoying. any others have the same issue? thansk.
meanwhile, i observed lots of EAC related messeges:
[ 3319.437500] EAC mode: play disabled, rec disabled
[ 3325.125000] EAC mode: play enabled, rec enabled
[ 3354.554687] EAC mode: play disabled, rec disabled
[ 3354.632812] EAC mode: play enabled, rec enabled
[ 3370.656250] EAC mode: play disabled, rec disabled
[ 3371.414062] EAC mode: play enabled, rec enabled
[ 3377.242187] EAC mode: play disabled, rec disabled
[ 3378.546875] EAC mode: play enabled, rec enabled
[ 3394.656250] EAC mode: play disabled, rec disabled
[ 3395.164062] EAC mode: play enabled, rec enabled
[ 3409.328125] EAC mode: play disabled, rec disabled
[ 3410.046875] EAC mode: play enabled, rec enabled
[ 3412.476562] EAC mode: play disabled, rec disabled
[ 3416.882812] EAC mode: play enabled, rec enabled
where does it come from? why so frequent?any harm?thanks.

with the latest maemo for N810.

i have this problem with my n800 when i'm running too many aps at once.

I have this problem periodically, sometimes even without many apps, but mostly with lots of apps or browser windows open.

oh, seems to be a common issue.
And from my observation, browser is always included in the application list. Was it caused by memory issue? I have already enabled the 128MB swap in the internal card.

That depends on what sort of harm you are talking about. It has caused disappointment for forum member darethehair (Darren Enns), who put a huge amount of work into porting gphoto2 for OS2008. His app works beautifully on Nokia 770 running OS2008HE, but on N8x0 it usually ends with total unresponsiveness of screen and keys, followed by spontaneous reboot and loss of data. Darren and most other N8x0 users have given up gphoto2 as unusable. For limited purposes, I find I can use it on N800 after custom configuration of HAL; but if I don't follow a strict procedure I still get caught by the freezing and rebooting.

As you have noted, dmesg output shows rapidly repeated switching between EAC modes, leading up to the freeze. This is true, even when the freeze and reboot are forestalled by promptly putting an end to USB host operation. As in your own case, there is no good reason for EAC to be doing anything at the time.

Nothing like this happens on the 770. I believe it is a serious bug in N8x0 running (many versions of) OS2008. Sorry to say, I don't know how to make a Bugzilla report. In any case, Bugzilla seems to be paying exclusive attention to N900 problems now.

Thank you for bringing this to the forum's attention. Now we know that it is not just caused by gphoto2.

Were you using USB host mode at the time of these incidents? The problem sounds very similar to the one reported to Bugzilla in https://bugs.maemo.org/show_bug.cgi?id=3281 . The Bugzilla resolution was WONTFIX , on the grounds that host mode is not officially supported by Nokia. However, if the same bug affects usage without USB host, there might be a chance of some action. You mention something about using the browser. What other work was the N810 doing?