Patching PS1 game to work on PS2?

[wildthing]

Just got my PS2(chipped 2 days ago). I've got no problem copying & playing PS2 backups, but have had problems getting my old collection of PS1 backups to work. Out of all the titles I've tried so far all the Pal versions seem to work fine but none of the NTSC versions will boot at all. Am I right to assume that this is the same sort of region lock-out as in the PS1?
I've tried region patching a couple of USA games with both Patch-It & Gamester region patchers off the PS Utils page and the games now load & play fine but the screen is all messed up (massive black borders)
Does anybody know if theres a region patcher that doesn't affect the TV output in this way?