BUG #5925: Files corrupted

The following bug has been logged online:

Bug reference:      5925
Logged by:          Castro
Email address:      flashed@iol.pt
PostgreSQL version: 9.0
Operating system:   Windows Server 2003
Description:        Files corrupted
Details:

I change Postgresql v8.4 to v9. Before that i bakup all databases. After
Postgresql v9 installed i restore the backup. One of the database has a
table that contains files(pdf, png, etc...).

When i tryed to open this files, the windows give me a error "File
corrupt".

Can u help with this error, why the change of postgresql to version 9
corrupted the files?