version 27 still transfers all data at the beginning of a song even when the checkbox for playback from ram is disabled.
My low power CPU is not capable sometimes of the extra load and is then stuttering for 1-2 seconds, very annoying.
If you don't have Memory Playback enabled, then it may just be that your system is too slow to handle playback.
Running
Help → Benchmark and posting your JRMark score, while including details about the track you are trying to play might be helpful. (DSD? 24/192 PCM? etc.)
I would try changing the pre-buffering setting and see if that helps.
Tools → Options → Audio → Settings → PrebufferingEither try increasing it to 20s or reduce it to 2s and see if either extreme helps.
The "Play silence at startup for hardware synchronization" setting may also help.
If none of that does, it might be useful if you download and install
Process Explorer and take a screenshot of the performance graph for Media Center when you start playback.
This might give JRiver a better idea of the problem, though I have tried demonstrating it many times before.
This post has an example of what that should look like.
It would probably be best to set the program to update every 0.5s before you start, and then let a few tracks play until the graph is full.