are these unsigned themes? Did you patch the uxtheme.dll file?
Take a look here for possible solution -
My problems started one day when I tried to boot into windows XP and the bootscreen wouldn't even show up. I tried to boot into safe mode, but that only resulted in a hard reboot. I decided then to run a repair install of windows XP which resulted in the OS coming back, but with several problems. Eventually, I decided to, yet again, repair install windows XP. This time, everything seemed to be working fine, except a problem I had earlier with windows explorer.
When I boot the computer, often times the shell's theme will revert to windows classic mode, and sometimes won't offer me any other visual theme. Additionally, upon running any .msstyles files, the display properties pop up, but it only displays the current theme and doesn't offer the style I just opened.
Any ideas on a solution to this problem?