vacuum full problem

Hi,
I am running pg 7.3.4 on linux red hat 9.0.

If I try to execute vacuum full analyze verbose, the pg vacuum some
tables and hang after this lines:

INFO: --Relation pg_toast.pg_toast_16408--
INFO: Pages 0: Changed 0, reaped 0, Empty 0, New 0; Tup 0: Vac 0,
Keep/VTL 0/0, UnUsed 0, MinLen 0, MaxLen 0; Re-using: Free/Avail. Space
0/0; EndEmpty/Avail. Pages 0/0.
CPU 0.00s/0.00u sec elapsed 0.00 sec.
INFO: Index pg_toast_16408_index: Pages 1; Tuples 0.
CPU 0.00s/0.00u sec elapsed 0.00 sec.

After rebooting I can vacuum without any problems.
I do not find nothing in my log-file that can point me to this problem.
Also the problem comes constantly by me.
Any idea or info about this problem?
Also I am using pg + java (jboss), but I think vacuum is working normal
with it and I have many instalations without this problem.

regards,
ivan.