MT3GS WiFi Fix
Okay so i updated to the latest CM7.1 RC1 and everything ran great for a week or two, and then all of the sudden the WiFi would no longer search or connect... so here is a quick fix.
Assuming you have a Rooted MT3GS with the same WiFi issue follow this steps to revive your WiFi.
I AM NOT RESPONSIBLE IF YOU BRICK YOUR DEVICE!!!
Download Files:
Android Optimizer Toolbox
Official CM7.1 RC1 ROM
Instructions:
1. Install Android Optimizer.
2. Run Android Optimizer.
3. Run [Un/Installer]
4. Select all Apps that you wish to back up.
(so you don't have to re-download them from the market one at a time)
5. Place the Official CM7.1 RC1 on your SD Card Root.
6. Run ROM Manager Premium.
7. Run [Install ROM from SD Card]
8. Locate the official CM7.1 RC1
9. Check [Wipe Data and Cache] & [Wipe Dalvik Cache]
10. Press [OK]
Then:
After this process the Official CM7.1 RC1 will be re-Flashed and you will have to re-input your GMail account info at start-up.
Once the phone has finished loading, you can now install Android Optimizer Toolbox once again and making your way back to [Un/Installer] and re-installing your backed up apps with ease.
Please Donate If this Tutorial Helps you! 
rockettpc
MyTouch3GS /CM7.0.3 /844MHz
www.rockettpc.com