There is an issue outstanding in WSS that is causing a few of the people who download our free Flash Web Parts grief. 

The issue shows up when anonymous users hit a web page with our Web Parts on it and they get authentication prompts.

I've gone into detail into how we get SharePoint data into flash here. We call owssvr.dll via HTTP get, pass it some parameters and get the xml data back. Great, this has been around and working since 2001. Unfortunately in WSS 3 (and MOSS) an authentication request is sent back for anonymous users even if all the settings are configured correctly. SP1 doesn't fix this either.

The issue has been open with PSS since late last year with no progress. Another conversation this week assured me this be actioned..still waiting.

Its a dismal situation and I apologise to anybody who has wasted time on trying to get our Web Parts to work.

I'm trying not to think about the resources been expended on Office 14 when issues like this remain outstanding.