I have been quite happy with how reliable *knocks on wood* my 508 recievers have been for me since I have had them, but I have been experiencing one recording problem lately. I know exactly when this will happen which will result in my 508 locking up. Let's say there's a show on at 7:00 and another at 7:30 on the same channel and I have both set to record. I am on that channel already and begin recording the 7:00 show about 3 minutes in by rewinding to the start and then hitting "stop at end of event". Unless I go live after doing this, if I am still watching from the buffer, at 7:30 when the next timer is supposed to fire off on this same channel, the reciever will lock up and I will be unable to do anything but get a "recording in progress.. yes, no, cancel" and I can hit yes over and over but it will ignore me and I will be forced to pull the plug for 30 seconds to get things working again. Of course my 7:30 show will not record. Has anyone else experienced this problem? I have had this happen twice to me in the past week, I guess I am going to have to remember to start going live when I am in a situation like this again. 
