iPod touch 3g with 2g charger

I've been trying to find a charger suitable for my third generation 32GB iPod touch, and while I've found many that are compatible with the 2nd generation iPod touch (and say nothing about 3rd generation iPods on the box), those I've tried have worked strangely. The iPod does charge, however when my iPod is connected and I try to type, using any application, some keys I didn't touch are written as if I had, and the touch interface in general works in a bit of a weird manner.

Has anyone else had this problem? Is there any risk in using a 2nd generation iPod touch charger with my 3rd generation iPod touch? Do I have to use a charger specifically designed for my iPod?