Empty the EPG with the config tool, delete your xmltv.xml file (or whatever you call yours), empty the cache directory, then update EPG from gbpvr's system menu. The new version works for me.
fla, I've done all that, and more, many times, trying to get a proper xml file generated.
I've been screwed over so many times by zap2xml that I switched to mc2xml.
I did everything I could, and zap2xml wouldn't get or write a proper xml file. It was always like 500-600 bytes, nowhere near what it should be. So instead of fighting with it, I tried mc2xml and it worked perfect the first try, and this was like 10 minutes after trying wtih zap2xml, so go figure.
You can never have enough tuners! Pentium Quad / 4Gb Dual Channel RAM / XPSP3 / 2 x PVR-500, PVR-250 / GB-PVR