SD Card unmounting while in use?

[Guest shasderias]

Nexus One using MCR r21 with A2SD+, my sdcard will occasionally unmount itself with the happy result of the phone crashing and burning. Pulling the battery and rebooting will cause the phone to hang on the loading screen (the one with the padlock), necessitating a second reboot to get it working properly. If the phone does boot, it will show up with no sd card mounted (which another reboot fixes).

Has anyone came across this issue? Trying to determine if it is a hardware or software issue at the moment. I have already tried reformatting/reflashing, basically using a clean install and doing a repartition. On the try list include getting another sd card and using my r20 image. Will try to get a logcat the next time it happens, but it usually does so when I am not at a PC. dmesg doesn't turn up anything useful, as it takes two or three reboots for me to even get access to a working phone again.

[Guest Aleksandr K.]

Similar problem - LG GT540 Optimus, Android 1.6, Kingston 4GB SDHC card. It happened twice while phone was in sleep mode. Phone makes sound, screen stays off. Upon turning phone on it does not show anything under /sdcard mount point. Only way to recover it I found out is to take off battery, wait 10 seconds, and put it back. Soft reboot through adb and removing/inserting SD card does not help. Couldn't read dmesg immediately because I was too far from my PC. Testing SD card in USB reader have not revealed anything. So far I reformated filesystem and waiting for it to happen again.

[Guest Aleksandr K.]

I thin I found similar thread here - http://androidforums.com/support-troublesh...y-unmounts.html .

No solution found.

Today I had problem repeated but in a bit diffrent way. Phone made 2 sounds instead of one with screen off. I turned it on and could see notification message "Preparing SD card". dmesg contained nothing directly related to SD card. I'm just wondering if it could be some background maintenance process which needs to remount sd card sometimes and which fails time to time.

[Guest shasderias]

Still no clue :S

Happens even when the phone is lying perfectly still, i.e. the sd card isn't wriggling loose.

I need to eject and reinsert the sd card for the phone to recognize it again.

My phone usually dies hard, SD card on nexus one isn't really removable without turning off the phone.

Can I check with you a few things:

1) Are you using AS2D or A2SD+ (or none?)

2) Probably unrelated, but does your Mail (not GMail) app often hang, taking up 50% CPU time, even in the background.

3) What ROM are you using?

What bugs me is that you are using an entirely different phone, but getting the same issue. =\