I have run into a problem with Sonar X2 producer version. I primarily use it for midi sequences using soft synths. When the sequence comes to the end, the sequence will not stop and continues to run. In previous versions of sonar I had no issue with this.
Any help would be appreciated.

suggest in the first case you ensure you have "stop at project end" ticked in the track window options....

Yes, as mystic38 says . . . and if it still continues to play past where you want,
you can go to the Event View and see if there are any midi events after where you expect it to stop.