Powertab Software Volume Adjust Question

Hey...Im having problems with the power tab software. When i play a song the midi will be workin fine for a period of time then suddenly go very quiet and i am unable to really hear the file unless i listen closely...but it is very bothersome lol. I was wonderin if anyone had this problem or knows of a solution....i check the volume control from the start up menu and the midi adjust is turned on full and i cant see any solution to this problem at all when i look around powertab. I also checked the guitar in source to turn it on....and it still goes like that. Re-installing the program does not work.....but it does go back to bein loud again but like i said earlier after a short period of time it does this.

NEED HELP ITS DRIVIN ME CRAZY lol

thnx guys for ur time