J.River MC plugin causes MC14 to become unresponsive, locks.

Anyway, does your taskbar freeze for several seconds, and drawn windows on the desktop become black?

No, I can't to reproduce the freeze

How about the time from when you first click play, to the time the song starts playing, and displaying stats in the tlb module; how many seconds pass?

Right after MC15 starts there are the delay about 10 sec before TLB "find" the player and show the stats, then if I click play MC15 begins play immediately.

Well, I'll make the special support for MC15 not via the Universal Player. I guess this will solves all the problems.