totle, it sounds to me like you have some other problem that has nothing to do with the AlienGUIse theme. Check your msconfig. I believe you may find something there that is lagging your system. It could be anything. I have heard people claim that they had no spyware. But, then they scanned their system and found tons of it. Try different Spyware scanners. Spy Bot didn't find most of my spyware for some reason. Some spyware even has the ability to disable the program. You might try uninstalling the spyware program. Reboot and erase the directory and reinstall it. It actually took me three different spyware scanners to find all the junk deposited on my computer.
It could also be bad drivers. If you are running multiple firewalls or virus scanners, that would also cause such a problem. I would try disabling all your unneeded programs in msconfig. Then, if your lag stops, you can track down the culprit that way.
I ran Spybot and it found no spyware. So, I installed Adaware and it found five spyware files. Then, I installed Spyware Doctor and it found fifteen spyware files. I'm pretty sure that my Spybot was disabled by a spyware program after I downloaded a EZ theme. I hear that ThemeXP files have loads of spyware too.
You may also bring up your task manager and check your CPU usage and available Physical Memory in the performance tab. It could also be a problem with your performance settings. If you install WMD drivers on top of your VDD drivers that could cause a problem. This could happen if you have automatic updates checked in your system settings. Or if you updated your video drivers before removing the old drivers. Most new drivers are using WMD drivers, and the installed drivers are normally VDD drivers. The list goes on and on.
If you really want to solve the problem, I would wipe the hard drive and start over. Then, you can track down exactly when the lag starts. This is the best troubleshooting solution. This way you start with a completely clean and lag free system. I do not believe that the problem is Theme Manager or Windowblinds causing your problem. But, you can uninstall THeme Manager and see if the problem goes away. The problem may also be conflicting programs. Like I said, the list goes on and on.