Despite my best efforts, I can't resolve a problem preventing Windows
Update trouble.

To cover the basics:

- Using HTTP proxy
- Unloading IP filters doesn't resolve the problem
- Both Win2K and WinXP workstations see the problem
- Read ahead is disabled in BM Setup / Caching / Cache Control
- Enable Persistent Connections to Browsers / to Origin Servers are both
checked in the HTTP Appication Proxy / HTTP tab.
- I've applied the current patches for BM3.8 per Craig's site, but I
didn't install the beta SP2; I stuck with SP1.
- I've run Craig's Tuneup.NCF
- I've cleared both the local workstations' IE6 cache as well as the
Proxy cache.
- I've added and as
noncacheable objects in Caching / Cachable Object Control.

Any further ideas are appreciated.