The TCL85.dll introduces a subtlety (actually it is TK85.dll). The 
MSVCRT90 is not the only dependency that can be in the manifest. The 
Windows.CommonControls.6.0 is used by TK85.dll. So, also for all Python 
extensions which have additional dependencies beside MSVCRT90, the 
manifest should still be included.

Situation:
- .pyd only depends on MSVCRT90: no manifest needed (will fallback to 
Python 2.6's own manifest and to WinSXS or the installation in the main 
Python folder)
- .pyd has more dependencies: manifest is needed. But, a wild idea, 
perhaps we could strip MSVCRT90 from the manifest? This is speculation, 
but perhaps the fallback to the manifest of Python26.exe will still 
work this way, and the runtimes will only need to be in a single place.

Anyone know of an easy-to-build example of a Python extension with 
extra dependencies?