I have just released a new tool that performs full uninstall of Classic Shell. You can try it and see if afterwards version 4.2.4 will work for you.
Download the Classic Shell Utility from here
http://www.classicshell.net/downloads/Run it and select the second option "Remove Classic Shell". Read the instructions carefully. Reboot after you are done.
If you want to keep your settings, you may back them up into XML file first. This is just a precaution. The utility will not remove your settings unless you check the option to do it.
Let me know how it works for you.