>The code is already running filter set to commands. I also have checked to make sure nothing is being redefined in differnt places. Any other ideas?

Okay, next I'd do a SET STEP ON at the top of code (maybe sandwiched in a logical so it won't hit the debugger the first time when there is no error to save time), and walk the problem through the debugger, see what you find. Or have you tried that yet? If not, try something like this, if there's no error the first time through:

1) At very top, Local (maybe Public for this purpose, in fact) call it say lDebugnow (default .F.)
2) also at top of code, after Local/Public decalaration, put the below code
3) at very bottom of code set lDebugnow = .T.

If lDebugnow
  SET STEP ON
Endif

I'm sure you get my meaning, you just want to debug when the problem hits, with all that code to step through.

No offense, but related is the main problem I have (and perhaps others) in trying to analyze this, is that you have one heck of a lot of code and actions for what is it, a listbox click? Makes it sort of hard to follow what's going on...usually I break up that much code into some methods, and then the error will show up probably in only one of the methods (with some luck), easier to isolate.

(Note: The Lostfocus calls look peculiar and unusual, that's the first thing that jumps at me aside from all the filtering. What's with those?