Incompatibility to older Versions of Plugin?

Here are 3 debug logs.

debuglog_2.1.0.9.txt: "Check module" - works
debuglog_2.1.1.x.txt: "Check module" - doesn't work

debuglog_2.1.0.9_Checkout_Error.txt: Here another module (project) was
selected to check out, which produced an error.

My colleague had Win2000 with VS 2005 and CVSSCC-Plugin V.2.1.0.7 - which
worked. Now he has installed Win Vista, VS 2005 and CVSSCC-Plugin
V.2.1.1.0. When he selects "open from Source control", enters the
modulename and path exactly as before, and presses the button "check", the
result is "Module not found on the server". (CVSROOT is okay.)
If he installs V.2.1.0.7, the same procedure succeeds.

We assume that in the old version of the plugin, a "module" was simply a
folder under the CVSROOT. The new version seems to use the file "modules"
on the CVS-Server to check for available modules. But as the old version
didn't enter anything in that file "modules", the new version doesn't find
any modules.
Is our assumption correct? Or what else may be the reason that the new
version cannot find the module? What can be done?
Thanks in advance