I have owned both the Leviton HCA02 and X10 XPCR and both exhibited the periodic lock up problem (this was back in the '90's). X10 made both models. The lockups were easily resolved by cycling the breakers the XPCR was installed on. In frustration I upgraded to an ACT CR234
http://www.smarthome.com/4821AC/HomePro-CR234-Amplified-X10-Coupler-Repeater-w-Repeated-Signal-Detection/p.aspx. The ACT CR234 has much higher output than the X10 models and is more reliable.
The king of repeaters IMHO is the XTBIIR from JV Digital Engineering.
http://jvde.us/. If I classify the ACT CR234 as a "flame thrower" repeater because of it's high output, I would have to put the XTBIIR in the category of tactical nuclear weaponry as it cranks out 30V or more of signal.
High PLC signal not only insures the homes power lines are well saturated on both phases, but also goes a long way in solving any noise problems (present in almost every home) and "signal sucker" problems. So filters on TVs, computers, switching power supplies, CFL lights, etc. are either unneeded or only needed for the most hideous noise offenders. In a previous home with the XPCR I needed 6 to 8 filters to remove noise. With the CR234, I need a filter on the microwave, but suspect the filter would be unneeded if I upgraded to XTBIIR.