userform mysteriously unloads
 

One of the functions on my userform will delete a sheet.

This funtion has been working for some time and now
suddenly after the sheet is deleted, the userform unloads.

When I try to use the step through funtion, "can't enter
break mode at this time" is displayed.

Even more bizzare... the sub calls after the delete are
running.

The only items I've been working on since this function
was working all deal with named ranges... I've check all
my names... all are functioning ok

Any ideas???? Thanks for the help!