Firefox doesn't work if the filenames are uppercase on the CD.I do not see this options in my winbuilder
An other chance: use Boot SDI instead of Create ISO
Using a recent version of CreateISO.script it is possible to keep filenames lowercase in the folder 'Program Files'
(e.g. CreateISO.script Version=35 available on the server 'livexp.boot-land.net').
But there is some script which doesn't work fully correctly if you use Winbuilder version 074.
Don't know whether this newer CreateISO.script Version=35 works with Winbuilder version=074 or not, didn't try myself.
I think also this FireFox 3.0.3 script needs a newer Winbuilder version