I'm sorry I have never experienced what is happening, but I wish you would have run it by us what you were going to try, I certainly wouldn't have used this msconfig option as the only way to change it is to be able to get in and run msconfig again, so if you experience a problem you are trapped.
This suggestion is also fraught with possible consequences, but you are between a rock and a hard place with few options remaining.
If you are able to boot into a DOS prompt rather than into this loop you might be able to edit boot.ini and remove the /safeboot that you added. If you screw up the boot.ini file you are royally screwed.
It is a long time since I played with DOS so you should investigate making a copy of it just in case, something like copy C:\boot.ini C:\boot.old (this however, didn't work for me since I was in windows using a command window, so the file was a hidden file perhaps that was why.
You could also try booting with the windows CD and try to get into the recovery console and try the last good configuration, that may correct the problem. You should investigate how to get into the recovery console (google search, etc.) and print it off before contemplating this.
http://support.microsoft.com/kb/314058 or
http://www.kellys-korner-xp.com/win_xp_rec.htmBoth of the above options are ones of last resort I would suggest the recovery console first as you aren't tampering with boot.ini.