Okay so basically following my tut. Have you changed brand of CDR your burning to? Try a different cdr as many brands change their supplier all the time and you may not be aware of that. Lower your burn speed and try them in someone elses DVD Player.
Also, I would suggest you make a CDImage (cue/bin files) instead of an MPG file and burn these out with VCDEasy. Nero has to many problems with SVCD. great for VCD, but lousy with SVCD.