I have received two reports of X10 universal modules misbehaving when close to a XTB-IIR. I was able to simulate the problem here when the universal module was on the same power strip as the XTB-IIR, but not when it was plugged into a receptacle across the room. The symptom I saw was that the universal module would turn on and then immediately off. Apparently it can be overloaded by the strong signal from the XTB-IIR (or XTBR).
While your problem appears to be different, you might try moving it either to a different circuit or further away from the XTBR so it receives a weaker signal. If the problem persists, then cause is likely due to something else. I have not seen this behavior with any other X10 modules either.
Jeff