The CSS in Site Settings/Stylesheet is not emitted.  Even if the "Include Portal.css" checkbox is checked (should be by default), it still does not appear to be emitted.  I have worked around this by moving my CSS to /Portals/_Default/Default.css where I could.

Cache management seems fairly broken.  Module-level caching settings do not appear to be changeable.  I have gone in to a module's Page Settings and tried to change the provider from File to Memory or Not Specified, gone back and seen it's still File/Inherited.  This even happens on built-in modules like Text/HTML.

The above seems to be causing some of my third-party modules to emit from the output cache, even though they are set at Duration 0 on the module level.  I have even changed the Host caching setting to None, authenticated caching to NoCache and this still happens.

Though not a solution, for the record I wanted to add that I have upgraded 2 sites to 7.03.00 so far and both times encountered the sudden lack of portal.css being emitted. I went to Admin/Site Settings/StyleSheets and checked "Include Portal.css" - it worked and things immediately returned to normal. So it will be interesting to see what is the cause and solution to your issue. Thanks - Jeremy