I had partition it with 1920 MB ext4 /sd-ext partition (rest was FAT32).
First ever problem was restoring /sd-ext backup using Amon Ra recovery (recovery-ra-thunderg-3.06-gnm) - after waiting about 3 hours I connected phone to PC and with ADB looked that unyaffs process is running, unyaffs was not killable (with kill and killall commands) nor reboot command worked, at last I pulled battery to stop it.
Another accident was moving /data/app and /data/Dalvik-cache to this memory card - after doing this I wiped Dalvik-cache and /cache (via recovery), then phone didn't boot. After about 10 minutes of watching CyanogenMod boot animation I connected phone to PC, tried to run adb shell and it couldn't connect to phone (I killed adb daemon before connecting).
When I connected this card to PC (using USB microSD adapter) and checked it with Check Flash it showed no problems.
The question - is anybody using Kingston SDC10/32GB in his LG P500?
I think either card that I bought is malfunctioning, either it is somehow incompatible with LG P500 (I don't know - may be it drains too much electricity)...
P.S. Kingston 32 GB class 4 microSD card works well in these conditions.