Had my R4 for a few months now, and I've been having trouble with games freezing during gameplay (sound stutters, screens sometimes go white or black, etc.) I've used two different MicroSD cards, one was a Kingston (Taiwan), one was a PNY (Japan, I think). I haven't had problems using the cards for storage, or reading/writing files to them. No slowdown in any games I've played, including Castlevania POR. Strangest thing so far is that in Geometry Wars, I get an actual error message when it freezes. Big white "EXCEPTION" on the bottom screen, followed by a list of hexadecimal memory addresses. If anyone thinks this will help diagnose the issue, I can post a picture. Any ideas? Anyone have the same issues? I've tried the paper/tape trick to keep the contacts in place, and tried reformatting the card, but nothing has worked.