Comment 3 for bug 120884

I encounter the same problem.
Instead of deleting the file .trash_entry_cache, I edit it:

Original file:
/dev/shm -
/lib/modules/2.6.20-16-generic/volatile -
/proc/bus/usb -
/var/lock -
/var/run /var/run

Edited to:
/dev/shm -
/lib/modules/2.6.20-16-generic/volatile -
/proc/bus/usb -
/var/lock -
/var/run -

Not sure exactly what the changes did, but it worked. After logout/login, the trash is back to normal.