Does anyone know about this? Unfortunately, a site user found the problem before I did.

I've tried it with inconsitent results with and without a proxy firewall, from multiple computers, logged in as multiple users and security roles. I don't see a pattern yet. Sometimes it works, most of the time it doesn't.

The permissions on the folder for the repository file storage are enabled for the repository user security role, both for read and for write.

No whitespace filter enabled.

Page State Persistence:  Page
Module Caching Method: Memory
Performance Setting: Heavy Caching
Authenticated Cachability: Public
Compression Setting: No Compression
Use Whitespace Filter: Unchecked

I do have IIS compression enabled. I currently have PageBlaster turned off, but I'll turn it back on once I have this problem sorted out.

Are there any other ideas about what could cause this?