You may be bumping against the polyphony for these instruments. Keep in mind that all the woodwinds are set (out of the box) to 1 voice polyphony to allow the legato technique to function properly. If there is no CC#64 (sustain controller) data in the track and two notes overlap or are played in succession quickly, the second note may or may not play. So, to get around this, you can 1: raise the polyphony for the instrument or 2: insert CC#64 data for the note passages to activate the legato mode. #2 is the prefered method of alleviating this problem.
I'm assuming this is the actual issue (since you are new to the program and it happened to me), although it could be something else altogether.
- In Audio Options - which sound driver are you using - it should be your soundcard ASIO driver
- somewhere you will be able to adjust the latency of your soundcard - try increasing it (or doubling the number of buffer samples until the problem goes away)
- check what is happening to your CPU load when the dropouts occur - maybe background processes are kicking in
- check what is happening to your on-screen mod-wheel during the dropouts, it maybe 'returning to zero'