That is strange, sounds like a timing problem you can try Universal's tech support tomorrow at (914)835-4484, or whomever you bought your MX from. I just got these in so have not had a chance to play much, nor have they been out long to really get a good feel for reliability. From the support I have got from Universal over the last couple of weeks, I think they are trying hard to improve their image so I am sure you can get warranty it turns out you bought a dud. I have tried their software but don't see any way to tweak the IR code like some of the other programs out there. Sorry I could not be of more help.
Bill
www.homeautomationnet.com