Yeah, that's probably it. I think Silver Strike came out to replace World Class Bowling, but it is too new to be considered by the Mame devs.
Do you know what the refresh rate is of your monitor? If it is at 60 hz, see if you can set it higher. If you cannot, you may need the latest Mame update .118u2. I doubt this update has been incorporated into the latest mame32 compilation. Therefore to use it, you may have to compile your own. Here is a snippet from the what's new:
0.118u2
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NOTE: If you are experiencing sound stuttering due to not being able
to run your display at >60Hz, please give the -speed option a try.
You should be able to run MAME at a small emulation speed decrease
in order to get the game under your monitor's refresh rate.