Class stops working...

Some time ago on Dick Kusleikas Daily Dose of Excel (dicks-glob.com) a
utility for putting additional stats on the status bar was posted. With that
idea in mind, I created a Class Module to show the sum and count of selected
ranges on the status bar so that you don't have to continuously switch
between them.
To keep the status bar updated, in the class module, I use€¦
App_Stats_SheetActivate
App_Stats_SheetSelectionChange
App_Stats_WorkbookBeforeSave

The problem is:
Every so often, the Class Module stops working and the status bar no longer
updates. I cant pin down whats going on when it stops working because I
only look at the status bar when I need the sum/count information€¦and then
notice that its not giving me the information. I have another Class Module
that also depends on specific events such as SheetActivate that also appears
to stop working at the same time.

Does anyone have any idea why a class module might stop working and yet
macros in Standard Modules continue to work? And, of course, do you know how
to get around this issue? I dont know if Im going down a blind alley but
it appears that macros that I specifically call work fine while macros
dependent on an event stop.

Any help would be greatly appreciated.

Thanks in advance.
Sincerely,
Gary Brown