In CDex, please open the CDDB menu and choose Read CD-Text to make sure that it's the actual CD-Text that you're seeing. What's the exact title that is shown there?
Just to be sure, does WMPCDText also show the expected CD-Text now? (you may have to use the Read CD-Text context menu option again to force a re-read).
I did some more tests on my Windows 7 system, but never got any garbage text either, not even on first plug-in use or the first disc read. Oh well
Are you using the 64-bit version of Windows 7? If so, then this is probably a known bug in WMP that you're seeing. My Windows Media Player Plus! plug-in already includes a fix for this bug, so I suggest that you try installing that. You can uninstall the plug-in again afterwards if you don't need it - the fix will stay on your system.
The software needs some particular service to be running? I have disabled some services in autostart...