If you have v4.00, these are the changes below, if you have a different version, just google TSPP Roms and you'll see a thread where this info came from.
Changes from Game ROM v4.00
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- *** THIS GAME ROM REQUIRES DISPLAY VERSION 5.00 OR HIGHER. ***
- Mystery award no longer gives the same award back-to-back in competition
mode.
- Mystery award no longer lights extra ball if one was already lit.
- Mystery award no longer lights special if one was already lit.
- Kwik-E-Mart standup now changes digits correctly in competition mode.
- HSTD Reset now also resets Grand Champion (there is now no way to manually
erase the non-grand-champion scores, they will reset themselves only on
the HSTD Reset Count adjustment). This is to address not being able to
change the default grand champion score.
- If an Otto award gets stacked in the display queue, it will now show the
correct shot that was doubled (previously it would generally always show
upper playfield at 2x scoring if it was queued).
- Homer's TV-lit speech now takes priority over Krusty's quotes again, and
will also be heard if the display effect doesn't get to run.
- TV start effects now stack after combo and other awards.
- Couch lock and multiball start animations now stack after combo and other
awards.
- Major award events (e.g. TV mode start, Otto award, Treehouse awards) now
only hold up the device they are associated with, not all kicking devices.
- Combo awards now awarded before anything else on a given shot.
- Itchy and Scratchy eject now double-checks to make sure the targets are
actually down before trying to eject the ball. It also waits until any
drop target reset process is complete before kicking.
- Otto eject now has more low-power kick table entries.
- Couch multiball start lamp effect now called from the display effect.
- Couch multiball start lamp effect now goes away properly if the start
display effect is blown off.
- New U.S. default pricing, 1/.75, 3/$2.00