Streaming Infopath form data from web server - strange behaviour in Fiddler trace

I have a simple aspx page that streams Infopath form data to the client. That then opens in the Infopath template on the client machine. Works fine.

However when I look at the Fiddler trace I see 7 calls to my aspx page - the original one from the browser, then several times more from the Infopath process. My form data ends up being downloaded 4 times - once by the browser and 3 times by Infopath!

Here's a link to the Fiddler trace file - if anyone can explain what is going on here I would be grateful.

How does Infopath even know about开发者_C百科 the aspx file & why does it need to call it at all, leave alone calling it several times?

Infopath (and actually most MS Office applications) has code which attempts to determine where a given form came from and then use the content from that server rather than a local copy. This is typically important to offer the ability to post updates back to the original source (e.g. a SharePoint site). Generally you shouldn't see multiple full downloads, although you certainly may see several HEAD, OPTIONS or other WebDav verbs.

(The Office team is working to reduce redundant downloads but this isn't trivial for a bunch of reasons).