This is probably more an IE/compression issue, but it's come up with our dojo efforts.
We've recently fired up gzip compression on the server side to shrink down our js files, including our custom-built xdomain version of dojo.js (from 0.4.1).
Now it seems that *some* users *sometimes* get strange behavior where the browser thinks it has a good version of dojo.js in its cache, but it does not.
The page ends up giving a lot of "dojo is not defined"-ish errors.
It seems this is documented in the following KB article:
http://support.microsoft.com/default.aspx?scid=kb;en-us;823386&Product=ie600
However, the article mentions this should be fixed in IE6, SP2, but we're not sure that's actually happened.
Has anyone else run into problems with gzip compression with IE6?
Some versions of IE 6 do
Some versions of IE 6 do have issues with gzip compression. The last word I heard from Microsoft was that a fully patched IE 6 (probably on XP SP2) should not have any gzip issues. Not sure if it is true though.
Unfortunately, it has been hard in the past to figure out which versions of IE have the problem. I think some devices like a netscaler or a CDN can figure out some of it for you (they automatically send gzipped or non-gzipped content based on some detection they do). Not sure those approaches are realistic for your application. Maybe just ask the users to upgrade to the latest version of IE 6? Or send non-gzipped stuff for those versions?