BUG #5439: Table crash after CLUSTER command

The following bug has been logged online:

Bug reference:      5439
Logged by:          Stefan Kirchev
Email address:      stefan.kirchev@gmail.com
PostgreSQL version: 8.3.3
Operating system:   Linux
Description:        Table crash after CLUSTER command
Details:

Hello,
I order to keep good performance on tables CLUSTER is done regularly on each
table every Sunday. Almost every time we loose a table which must be
recreated afterward. The error yield is:
pnp=# select * from  alcatel_bss_kpi_tmp.cs_hourly_kpi limit 1;
ERROR:  could not open relation 1663/16404/2426042: No such file or
directory
It is obvious the engine fails to replace the old relfilenode with the new
one.
Is it possible to recover the data from the pg_toast?
Is it mandatory to lock manually table with ACCESS EXCLUSIVE option or it is
done by the engine along with the CLUSTER command?
Thank you!