booktype vs plextor 708

[Jeff <jeff@owenstechnology.com>]

hi guys-

i know that Plextor doesn't support setting the booktype on this drive. but i
can't believe there's no workaround? burning discs which can be read in regular
DVD-ROM drives seems of rather high importance.

i'm using DVD+R media, my goal is to make iso9660's which can be read by a
couple DVD-ROM drives, notably the Apple Superdrive, and the NEC DV-5800A in my
Dell box. both have the latest firmware loaded.

i tested twice, with 4X media from Sony and Memorex. the discs mount fine in
the Plextor after burning, but both DVD-ROM drives fail to detect the media.

the exact command i used:

growisofs -Z /dev/scd0=/vol1/export/backup/archive-2004-06-09.iso -dvd-compat -speed=4

is there *any* way i can write a DVD-ROM compatible disc with my
plextor 708? with any software? would using -R media instead of +R make any
difference? or should i return it? can anyone suggest a different USB2
external burner of similar quality which allows setting the booktype? 

thanks,

jeff