BUG #6248: Stack Builder fails

The following bug has been logged online:

Bug reference:      6248
Logged by:          Joanna
Email address:      asia123321@op.pl
PostgreSQL version: 9.0.5 and 9.1.1
Operating system:   Windows XP
Description:        Stack Builder fails
Details:

I am not able to install and of the contrib packages since installer fails
to parse application-2.xml. I am using proxy, it seems that the file is
being read, possibly encoding issue?
The error occurrs each time and can be reproduced on my machine.