CheckFolderVersion() doesn't work properly

[aryeht]

Hi!

I have two versions of my SW, 29.12.05 and 29.12.06, where the latter is a very simple patch of the former. Version 29.12.05 has been installed by SF7, including writing to the registry of all relevant info (application name, product name, version number etc.).

Now I try to patch this version by a VP2 project that contains the two above versions only. I've defined the current version by the registry key only, with the main application of my SW chosen as a single key file.

The patch fails to determine the installed version correctly:
CheckFolderVersion() returns "29.12.06" instead expected "29.12.05". Moreover, when I duplicate in the VP2 project one of the two versions (no matter which of them) to a 3rd one, named, say, "ReallyDumbVersion", then CheckFolderVersion() returns "ReallyDumbVersion"!

If you can explain the internal logics of CheckFolderVersion(), I believe it can help me to overcome this problem.
One more detail: I install my SW N-O-T under C:/Program Files.

Please help!