[popcornmix]

Do you still think this maybe a bandwidth issue?

It is an underrun/buffering issue. That is usually caused by insufficient bandwidth (e.g. network), but high CPU can also cause the same symptoms.

You have two suspicious things in log file.
One you have "Extract thumbnail and video information" enabled. It's recommended that is switched off on Pi, as it's a very expensive operation.
Second you have a broken SQL database setup:

Code:

19:56:55 1639.709595 T:2724197456   ERROR: SQL: SQL error or missing database
                                            Query: INSERT INTO streamdetails (idFile, iStreamType, strVideoCodec, fVideoAspect, iVideoWidth, iVideoHeight, iVideoDuration, strStereoMode) VALUES (529,0,'mpeg2video',NaN,0,0,6500,'')

which means instead of each file being "extracted" once, it happens every time you play it, because the extracted data couldn't be stored.