I never experimented many weird compiler behaviour since I use PicBasic Pro myself, and I use it since over 10 years. Most of the time I got Error Code #18 to #24... which are located 'round 18 to 24 inches behind the keyboard

I can't comment Melabs programmer I don't have it, but I do have PicStart Plus & PicKit 2 (and others). Both gave and still give me good results.. But yeah, I heard a lot of weird programmer behaviour here and there.