I have also had this issue with my new RioCar player (with 2.0b3). However, I "think" I have determined that it is the remote, not the player that causes the problem. I borrowed a friends Rio and Kenwood remotes to try and debug the problem...

Both of my friends remotes worked fine. I tested all three batteries and they were fine, but just for the heck of it I swapped batteries on the two Rio remotes. Same result, his worked, mine did not. Then after swapped the batteries back both Rio remotes were non-functional! I pulled both batteries again to re-check the voltage - still good. I put them back in and now they all work and I haven't had a problem since.

I don't know if the remotes stopped transmitting or if the signal they were putting out was just garbage.

Just my observations...
-Jeff