I'm not seeing any crash reports from you under the email address you're using for these forums. Did you use a different email address when you sent them in? We're pretty good about answering our emails within 24 hours.
This is happening with version 8.1 build 418? If you have an older build, you should update to get all the bug fixes.
The next time this happens, quit Mixcraft and send us your Mixcraft-log.txt file.
To find the mixcraft-log file, highlight the following line and press Ctrl+C to copy it:
Press the Windows Key+R to pop up the Run box in Windows. Click in the Run box and press Ctrl+V to paste in the line from above. Finally, click OK to go to the location of the mixcraft-log.txt file. Submit an Acoustica Support Request
and attach the log file along with a brief description of the problem.