I found what was causing the overflow error message on some maps and fixed it.
I also created a new version of Scm Toolkit that uses the Mpq Control I created. The Mpq Control still has a few bugs left in it, though. I will keep the old version that uses mpq2k on the downloads page and update it with other things that don't have to do with how it modifies mpq's until I can get the bugs out of the Mpq Control.
I created an ActiveX control based on the mpq archiver by Andrey Lelikov. It is easy to use and has a few more features than the original mpq archiver.