My first visit to this forum, so please be nice! Just hope someone can help. I've got a pretty complex VBA project that I've put together containing around 150 subroutines, 15 different user forms and a whole heap of untidiness thanks to the organic way in which I've developed it over the past 12 months or so.

I've just stumbled across two issues in my final checks on the project:

1. I've got a combobox on tab 2 of an 8 tab multipage. Each tab has a button at the bottom which advances the user to the next tab, the previous page then being locked down and inaccessible. I set up a subroutine counter, so that every routine logged when it was accessed. For some reason the combobox_change() routine for this object, once activated, continues to be accessed long after the value is selected and the relevant page disabled. By the time the form completes its running, this routine has potentially been accessed 500-1000 times!

I've managed to nip this in the bud by adding combobox.value="" once the combobox input has been used and recorded on the data storage worksheet in the underlying XLS, but it's rather a clumsy solution to a problem that - as far as I can see - shouldn't exist.

The combobox is definitely not changed by any other events or code lines, as I've searched the entire project, and it doesn't have a cell-link, so there's no question of an underlying cell being changed either. The Change event is supposed to trigger when there's a change of value, but Msgbox reports confirm that the Event is being triggered when there has in fact been no underlying change. Most puzzling of all, combobox.enabled=false and combobox.locked=true don't stop the macro activating either!

Is this a known bug, or is there some underlying thing going on here!?

2. I've just sent my project out for wider examination, and it's immediately been flagged to me that it doesn't work on Mac Excel. Are there simple steps required to convert the sheet, or is the possibility of a multi-platform project pretty much dead in the water?

For info, I'm very much an amateur excel enthusiast with no formal training who honed his programming skills on the ZX Spectrum (10 Print "Bum", 20 Goto 10), which probably goes a long way to explaining why my sheet is somewhere over 20,000 lines of code!