Going from Cinema rate to video rate without using a smooth conversion is always going to create issues. Compressor is marginal at best. I use After Effects but Cleaner is better.

It's an extra step but if you take your web clips and throw them into FCP or AE, convert them to uncompressed in one batch and then convert them back to AIC at 30fps. This usually alleviates the glitches I have seen.

An idiot check is to verify you are not 29.97 but actually 30fps.

You can also hard lock your refresh rates to 29.97 if you have that as your native.

I feel your pain. I had all kinds of issues with this on the opening acts I had for Tay as well as her own audio source files.

Honestly, as much as I love Catalyst. I still use an HD Doremi anytime I have Audio playback with video. Of course I do get funny looks when I do this and use the deck control from Catalyst to operate the playback. Who cares as long as it's solid.