We also get the 504 on all the sites hosted by http://www.viadesto.com/.
The sites will work about half the time. We have NW5.1 sp8 BM37 sp3 plus
bm37fp4e. We are using Craig's proxycfg file.

It happens with both IE, mozilla, and Firefox. I have tried not caching
the site, and that make no difference.

We can access the sites fine from outside the firewall at all times. We
are trying to work with their tech support, but they only want to blame
our proxy server.

Thanks for any help,