Certain sample based VSTi plugins can suffer from audio drop-outs using offline mixdown. This typically happens if the samples don't fit the computer memory. In this case realtime mixdown can be used to record a master file.
Follow these steps to record a master file in real time:
This way you can record a stereo .WAV file that can be used for CD burning etc. Note that this file will always start at position 0, if you want to "top" or "tail" the file (remove unwanted parts at the beginning or end) you can open the file in a track and use the track editor's Export option to export the part you want to a new file.
Audio CD's always use a sample rate of 44.1 kHz. If you did not use a sample rate of 44.1 kHz use the Sample Rate Converter. Pro edition users can mix down to a 24 or 32 bit file in order to avoid rounding errors. Note that the final file that will be burned to CDR must be a 16 bit file in any case.