upgrade to debian unstable.
Debian testing is mostly for developers. It's were the packages slated for the next OS are kept in limbo. Right now the next OS is nearly put together so it works. Actually unstable is more stable then testing as far as reliability is concerned.
If you want to use testing, learn how to make it a hibred between testing and unstable, that way if a package isn't aviable in testing then it will install from unstable.
Try upgrading to the latest kernel, too. Right now I think it's 2.4.26-1-whatever. Could be that the kernel itself was damaged during the hardware problems...
Also should have the latest wireless drivers, too. If it's a prism2 chipset they have a seperate package for that, although you may still have to install the firmware stuff seperate. They also have a pre-compiled nvidia version package for that kernel, too.