For those who have updated their system to Windows XP SP3 RTM and need the patched uxtheme.dll, here you go:
I hacked it myself and it is indeed the RTM (v5512) file, not one of the Release Candidates. An easy way to patch it is using the program “Replacer“! As with most things, buyer beware… if this kills your PC, sorry! Here’s a screenshot of it doing just fine on my machine:
UPDATE – Now with Checksum goodness!