Anyone Have a similiar problem

Hi,

Now i have not used backup Exec in years but now having to use Backup Exec 2010. Now to the problem, I have a tape library and that has two drives I use two tapes for the daily. Now one of the jobs runs for 8 hours the other runs for  1 - 3 hours (both drives are used). Now i have set another job to run two hours after with a time window of 3 hours and it keeps on saying missed window. Now the append status on the dailys is showing 1 day. So my thought is that it should take the tape that thats been used for the 1-3 hour job and append to that tape as the other tape and drive is in use ?

Kind Regards

Scott