Then I don't undetstand when you wrote earlier...
Skipping regular Ext...
from your desktop.
Add whatever X/GUI you want to your regular extensions.
Update. Went to visit friend with an Windows XP NTFS machine.
I took a TinyCore-4.2 and a CorePlus-4.2 both on cdroms.
Both cdroms booted to X/GUI as expected.
If I cannot reproduce then I cannot address.