Reading ok, trouble writing

I have slide running on two servers, call them A and B. The slide
setups are identical, as far as I can tell.

On both A and B I can retrieve files in a web browser using the slide urls.

On A I can connect to the server using the 'Connect to Server' feature
of my Mac Finder, and I can view and update the webdav, but I cannot
connect to B in the same way. I get the message:

"You cannot connect to this server because it cannot be found on the
network. Try again later or try a different URL"

I'm also unable to update the slide server on B programmatically, so I
suspect there is some general problem writing to slide on server B and
its giving me that cryptic message on my mac. (The same code on A
works fine)

Any thoughts on what might be the problem, or suggestions for figuring it out?

Thanks

Seth