From the Connectix web site at www.connectix.com:
"All versions of CDU and CPU [Connectix PowerBook Utilities] are incompatible with Mac OS 7.6. The symptoms of the incompatibility are cosmetic: garbled video in the menu bar, windows, and dialog boxes. Because there are no workarounds for this incompatibility, users of Mac OS 7.6 need to remove or otherwise disable CDU/CPU.
To remove CDU or CPU, run the CDU/CPU installer and click the REMOVE button. Alternatively, the CDU control panel can be disabled with a startup manager like Conflict Catcher or Apple's Extensions Manager.
At this time Connectix does not have any updates planned for CDU or CPU. New information will be posted, to our web site, when available and we will continue to offer technical and customer support for CDU and CPU users. If you have questions about this issue, please contact Connectix Technical Support."