im using a realtek sound card, im trying to bounce my midi to an audio track but the midi is currently using gs wavetable synth, and i know your supposed to use the sofsynths to bounce the track, but when i insert a soft synth into the project the playback button and audio engine button is disabled , when i remove the  softsynth the playback button works, and when i choose a sofsynth in the fx box of an audio track the sounds of the softsynth is heard, so i was wondering if someone can give me any advice?
 
thank you

Try Inserting a Soft synth then Copy the midi from the Wavetable Midi to the Midi of the soft synth then mute the original Wavetable synth midi.  Or better still insert the soft syth and record the midi straight into the soft synth.
 
Some of your problems may be caused by the sound-card, On board sound cards have a bad habit of not playing nice with a lot of DAW software SONAR or otherwise.
 
Some other system spec's may also help with solving your problem.