If you're doing the "hack" I think you are, doing so expressly violates your Terms of Service and if detected (which is extremely unlikely, BTW) could result in termination of your service.
I'd suggest using the Free Wireless Tether app (
http://code.google.com/p/android-wifi-tether/) instead since you're already a root user. It
does support infrastructure-mode to act as a true wireless access point instead of just an ad-hoc network,
without violating your carrier's ToS.