I literally just ran into this problem this weekend after reinstalling Win7 with SP1. My previous install didn't have SP1 installed, so I was much surprised when making any change in MC Studio after SP1 would cause 7MC to crash on loading...
In any case, after much research, I found that there are two halves to this fix, and only one of those two halves was posted above.
The first thing you need to fix is the StartResources.dll
file located in C:\\ProgramData\\Microsoft\\eHome\\Packages\\MCEClientUX\\dS M* (where * might be a 1, 2, etc.). Simply renaming this file or deleting it will take care of the first half of the problem, however any kind of windows update might put it back and you'll have to fix it again. There are scripts you can find online to scan this folder and rename the file if it ever does get put back. I didn't try any of them as once you get MC Studio to work I don't imagine needing to tweak with it on a regular basis, and it's easy enough to perform this step again at that time.
The second half of the problem involves copying a few updated files into your MC Studio directories so that it's working from the right baseline. First copy the files Microsoft.MediaCenter.dll
from your c:\\windows\\ehome directory. Now you'll have to paste them into a directory that looks something like this: C:\\users\\*your_user_name*\\Appdata\\local\\Apps\\2.0\\*hug e_string_of_junk*\\ You'll have several folders whose name looks like a huge string of junk, but you're looking for the one with MediaCenterStudio.exe inside of it, and a bunch of other MC Studio files. Just open them at random until you find the right one, then paste those two files.
Next, you need to copy ehres.dll
from your c:\\windows\\ehome directory. These two you paste in c:\\ProgramData\\Media Center Studio\\Backups.
With those 4 files pasted and the StartResources.dll file renamed I was able to fully customize my start menu strips just like they used to look pre-SP1. I take no credit for the fixes, in fact I have no idea how they work or whether all four of those files are required to be moved or if you could get by with just 2 or 3 of them. I found the various fixes through Google searches in bits and pieces, mostly scattered around the www.pcmediacenter.com.au
forums. Hopefully this information is helpful and I didn't mess up any of the directory names too badly