I literally just downloaded SP1 for 7, and I am having the exact same problem on my 32bit desktop. My 64 bit machine, I just downloaded the latest version, and everything is working fine. It is only the 32bit machine having a problem. I am getting the same error message as you are.
DisableTaskBarOnTop is seriously one of my favorite programs. Tweaker, if you are still working on this let us know what might help.
Am I the only one seeing this problem in 32 bit ?
On a second 32-bit machine where I tried, the same problem occurs. Before my Windows 7 SP1 update, your tool worked perfectly on these systems, so you see the picture.