JRiver playing music slightly too fast

[Alobar]

I've been using ITunes but never really liked it that we'll, then the other day I noticed I had loads of duplicate music files in different bit rates. I was trying to weed out the 128 kbps files in favor of the larger files but with iTunes it was cumbersome as it wouldn't delete the files from the HD, just from the iTunes list. I downloaded JRiver trial version and was immediately impressed that it easily listed all the duplicate files and then I could manually select all the 128 kbps files and delete from the hard drive with one mouse click. Since then I have loaded the companion app for my nexus 7 tablet and for the most part been a happy camper. The problems started with some older downloaded iTunes music in protected mode which would hang up JRiver. I finally removed those songs and then tonight I started noticing the music was playing too fast. Not a lot but just enough where if you were familiar with a song you could easily notice the difference.

My question from all this is could this be an operating system issue? I have never noticed this with iTunes or Amazon player and would hate to blame JRiver for this if it turned out to be win 8.1. Still have 20 days to decide whether to spend the 50 bucks for JRiver or find something else to use. Has anyone else ran into this issue of a player playing music at a slight off speed? I really like JRiver interface, lots of dials and switches to play with, and the tablet app is outstanding for a remote control, but I cannot tolerate music playing even slightly off speed.