Can't Update Web

This is driving me around the bend. We have a W2003 server running
IIS 6. There are many functioning web sites. I need to update one
that was created with Visual Interdev and uses Front Page Extensions.
It's a subweb within a master web. So I have www.mydomain.com and
want to update the subweb www.mydomain.com/MySite. I keep running in
this circle:

- Make changes, Save in Interdev. Error: The folder /MySite is
marked executeable. You cannot place files in an executable folder".

So the fix to this, is to set the execute permissions to "Scripts
Only". Fine. I do that.

- Make Changes. Save in Interdev. Error: "Could not update file
blah blah blah. An HTTP Error ocurred." The MS article I found
mentions not to select any vti_bin folder when changing the
permissions but it never prompts me for any additional folder/web
permissions. But now Interdev won't do a thing so I go to the web
server to check front page extensions. The browser tries to load
fpadmdll but just spews a browser full of garbage. That's because the
web folder isn't marked as executeable so I go back and mark it
executable, check fp extensions (works now) and it fixes some security
error.

- Back to Interdev. Save. "Folder is marked executable". Well of
course it is, I can't use the FP management utilities if it isn't.
Fine. Mark as Scripts only.

- Save. "Could not update, HTTP error occurred"

Grr... Please save my sanity. What can I do to ensure the web can be
updated AND I can use the FP management pages? (fpadmdll)

Thanks!