I purchased a PNY 256 GB 3.0 flash drive board says to format it but comes back cannot format.I used other flash drives up to 64 gig no issues.is it because of 3.0 instead of 2.0 or is the capacity to large.i have about 95 gigs i wanted to put on it of mp3.i read that other people used up to 512 and worked.i formated it on my pc first when would not work and put a few sample files on it,but would not load on keyboard,then tried to format on keyboard and would not format.what brand should i use and also have a issue when using flash drive with mp3 songs on it selecting voices on right 1,2,3 lag time with buttons turning on voices and also the lyrics on screen seem to be a little out of time with the music.i have the latest version firmware 1.3