I have the same symptoms:

1) USB mass storage doesn't work from UI. Under Linux it shows the partitions for a while and then they disappears. I tried with different distro/kernel versions. I didn't try on Windows. But the mass storage works correctly from the bootmenu (i.e. no UI).

2) Also fsck runs on boot on user data and card which delays the boot process a bit. I always shut down the phone through the power button and I don't touch battery / open the phone after the shut down. The filesystem doesn't seem to be corrupt - the fsck from the bootmenu doesn't reveal anything. The same for fsck through USB mass storage (mass storage initiated from the bootmenu). I will also try to remove the card and run fsck on the external machine, but I doubt it helps.

Another thing I noted - ICQ stopped working. Other than that everything is OK. I am going to look more deep on all these issues, but any hints/tips are highly welcome.