Hi all,
I'm developing a c# excel addin and in order to make it work I have added a
new handler for the SheetChange event.
This handler modifies some global (addin scope) variables in order to
determine if some row/columns have been deleted and uses the UsedRange
attribute.
After that it become impossible to UNDO the modification.

Could anyone help finding out the reason and fixing it?

Thanks a lot for the help,

faffo1980