It can supply about 40mA/IO pin. Hmmm, i guess that does seem a bit low. should i try driving the FET with a little 2n2222?How much current can the microprocessor pin source and sink? This current needs to charge and discharge a pretty big capacitance which will slow things down a bit.. Try to look at the waveform with an oscilloscope if you can. You might be greatly surprised at how slow it is and how much time is spent in the linear region.