This tip comes in from Bill Auerbach:

An interesting situation came up. In some cases, Power++ 2.0 programs will badly crash Power++ 2.1, the application, and Win95 when ported and run under Power++ 2.1. Apparently, the 'Top Most' bit in the Extended Style word can become set in Power++ 2.0 which is harmless because it is stripped when the form is loaded. In Power++ 2.1, it is no longer stripped. Furthermore, for most controls you cannot access the Topmost property at design time. If it is set for a control on tab form page, the program will hang as described. Fix21 will go through all Form files in a folder clearing the TopMost flag. If you use TopMost, go back to those forms and re-enable the style. Fix21 displays a list of files and the number of corrections made so you can monitor for real Top Most styles versus those set by Power++ 2.0.

The program mentioned is available for download here.