FATAL: bogus freespace amount

Hi,

We are facing the following problem during the PostgreSQL 8.2.4 startup in a
Windows XP/SP2 box:

2008-03-31 13:35:12 1: LOG: database system was interrupted at 2008-03-31
09:45:44
2008-03-31 13:35:12 2: LOG: checkpoint record is at 0/7588FFD8
2008-03-31 13:35:12 3: LOG: redo record is at 0/7588FFD8; undo record is
at 0/0; shutdown TRUE
2008-03-31 13:35:12 4: LOG: next transaction ID: 0/100487; next OID:
909454
2008-03-31 13:35:12 5: LOG: next MultiXactId: 1; next MultiXactOffset: 0
2008-03-31 13:35:12 6: LOG: database system was not properly shut down;
automatic recovery in progress
2008-03-31 13:35:12 7: LOG: record with zero length at 0/75890038
2008-03-31 13:35:12 8: LOG: redo is not required
2008-03-31 13:35:12 9: LOG: database system is ready
2008-03-31 13:35:12 10: FATAL: bogus freespace amount
2008-03-31 13:35:12 1: LOG: startup process (PID 856) exited with exit
code 1
2008-03-31 13:35:12 2: LOG: aborting startup due to startup process
failure
2008-03-31 13:35:13 1: LOG: logger shutting down

What can be done to bring the system up again?

Thank you in advance!

Reimer