When I quit the VBA editor after making an entry into any module an attempt to enter data into a worksheet only allows i character to be entered. Sometimes I can use the menu bar to enter more characters but not always. If I just enter the editor to examine the code and don't change anything this phenomenon does not occur. Restarting Excel solves the problem until I enter the VBA editor again.

This wasn't the case several years ago. Is this a change in Excel or is it a bug of some sort?