Hi, i think i fugured out what causes the plugin not to work on many systems. I'm not sure if the plugin i have is the latest (March, 26th 2005), but maybe the problem is still the same:

When you use the depencency walker to examine the plugin you'll see that the plugin uses the debug versions of MFC 4.2 and VC runtime (namely mfc42d.dll and msvcrtd.dll in the Windows\system32 directory).
These debug files usually are only on systems with Visual C++ 6.0 installed to allow debugging of developed applications. If these files are not found you'll get no error, but the Plugin DLL won't load.
To solve the problem, when compiling you'll have to set the "Release" Build option to link to the release version of MFC and VC Runtime, which are commonly preinstalled on most systems. If not, they are at least redistributables which can be obrained by Microsoft (for free of course).
For the meanwhile, the Plugin will only work for people which have Visual C++ 6.0 installed (or an application that distributed the debug dlls although thea are not considered redistributable...)

Hope this info helps you to solve the problem.