Sounds like you are doing everything right mate, Try this
When you use CDgenPS2 to makup your disk do the LBA fix and at the bottom of CDGenPS2 screen you will see total time you MUST keep this UNDER 72 mins including everything(the three files and the AVI)
Then make the Image, do it as Bin+cue files NOT ISO
Then burn with CDRwin, But fireburner should work fine if you havn't got CDRwin, Its just that i use CDRwin, with no probs at all.
Also If you are using CDRW disks then that could be a problem, use 80 minuite CDR's
Hope that helps and Please let us know how you get on M8 !!!
Voted Best Avatar on PS2newz 2003 !!!
PAL V7 with DMS3,
XBOX V1.1 with Xecuter2.2 PRO Custom Hacked/Edited M$ Dashboard, Self installed and Blue Eject light, Clear jewel