Are you using the latest version of Stiebler's patch? I remember that he made the installation a little bit easier. Maybe that will help you in installing.
Also Wreford - Brown is planning to make SH3Commander do the dirty work on appending Stiebler's patch:
http://www.subsim.com/radioroom/show...08#post1927408
His work is not yet ready though...
In the mean time two simple solutions come to my mind:
1. did you to remember to make a new SH3.exe?
2. are you sure there are no ; signs in front of the lines you added?
If these don't work, maybe you just need to take Stiebler's addon totally off your computer and do all the installation steps all again from the beginning.
EDIT: oh yeah, it might be that you don't have Stiebler's addon - anyways what I wrote before the edit, is still valid...