Thanks puppydogbuddy,
That page does address the general issue that I have, unfortunately I haven't been using any code in my solution - The combo boxes are using items I entered in their Row Source, etc... So it doesn't seem to fit my problem.
I tried implementing the general ideas from that page but I guess I didn't do so well, as it was still giving me the same issues - The alpha field I have wasn't matching anything if I chose "ALL" from the list, even though I had a (hidden) second column in the combo box that held an asterisk for the row, and was being referenced (I believe) by the criteria field in the Query.
The numeric parameter was even worse, in that it just gives a type mismatch still, when I did the same for it, and choose the "ALL".
Perhaps the problem is in the way that the query references the data from the combo box? I have named the hidden column with the asterisk against the "ALL" as the bound column for the combo box, but perhaps there is more to it? Do I need to include some sort of "Like" with the query criteria?
I'm confused. :(
Thanks for any suggestions any one has. I had hoped that this was a common thing that people would have done, to include an "ALL" option along with selectable items on their forms, and have it effective ignore that field in the query selection criteria.