Va!n: The new .exe's won't work under win2k for two reasons:
1. Crinkler's .dll import code retrieves kernel32.dll (for LoadLibrary etc) using something called the PEB trick. Basically, the PE loader loads a list of some lib's by default when any .exe is started, and kernel32.dll just so happens to be in said list. However, Win7's loader loads the lib's in a different order, so the original trick won't work. So the new Crinkler uses a similar method to the PEB trick, though it reads from a different list of lib's than before. This method works on Win2k SP4 MOST of the time, but unfortunately not all the time.
2. Win2k PE files are required to have at least 1 proper .dll import (which was lz32.dll in earlier versions of Crinkler...the lib isn't important; just has a short name). But due to instability issues from above, it's rather pointless to still have this in the structure, so it was removed (and this is why new Crinkler files are about 14 bytes smaller than before).
So those are the two reasons why the new Crinkler is incompatible on win2k - it was sacrificed for win7 compatibility.
