J-Pac/I-Pac setup causing screen splitting...

[Gage]

I recently finished a custom control panel for use with my existing Captain America arcade cab.  Before building the new control panel, I had a J-Pac hooked up to my existing control panel and all of the games appeared to be running smoothly.  When I finished my custom control panel, I added an I-Pac2 to the setup, as I wanted to add the Player 3 and Player 4 controls to the mix.  I noticed that some of the games that used to run at full screen (Simpsons, G.I. Joe), now appear to be split into four identical screens.  It appears to be a resolution issue or something, but I'm not sure how/why it got changed. 

Is there a setting in MAME that could have been accidentally changed during the I-Pac programming process?  Any ideas?

FYI, I'm running soft15khz on my video card and I run Hyperspin as the front end.

[Gage]

Update:

After disconnecting my PC from my arcade monitor and connecting it to a standard LCD screen, the Simpsons game plays in a single screen, not split into four identical screens as it did on the arcade monitor.  So I'm not sure if this is a result of the IPac installation or the soft15khz configuration.  Could it also be the resolution setting?  I had 640x480 for the PC to work with soft15khz and my arcade monitor and switched it to a higher resolution after hooking it up to the LCD screen.  However, I think I have the option in MAME to auto-adjust the resolution per game set to "ON", so I don't know if that would be an issue.  The only thing that makes me think it's not soft15khz is that I didn't change any settings on soft15khz after installing the IPac.  Simpsons worked perfectly before installing.

Any thoughts?