Working on a public facing SharePoint Foundation 2010 site with anonymous access enabled. Anonymous/authenticated access to content works as expected without problems so far.
Recently I went into creating a custom theme (thmx) to change some of the colors which works without a hassle while testing it as authenticated user.
However, as soon as I started testing as anonymous the theme is not applied at all?
So far, I've tested with IE 8, Firefox (latest), Chrome (latest), Safari (latest), Opera (latest). All with the same issue not displaying the applied theme to anonymous users but display to authenticated users.
To make sure it is not service pack related I ran a test with Foundation 2010 RTM and Foundation 2010 SP1 with the Oct 2011 CU with the same results.
Also, to rule out any custom stuff I've tested again with a plain vanilla Web application/Site collection/SPWeb and used only the built-in themes of the theme gallery, but it didn't work either.
I've also double checked that the Theme Gallery has no custom permissions applied (it is set to the default to inherit from the parent SPWeb).
I'm running out of ideas what else could be wrong.
Any ideas? Can somebody reproduce that behavior?