If you are using Virtual Machines and snapshots there is a possibility you had run into a issue where the GUID of the package is always the same in the first sequencing try after reverting to a previous snapshot. I asked the support if this could be resolved and they said it must be because I´ve taken the snapshot with App-V Sequencer opened, but I did not take the snapshot with App-V Sequencer opend but still I´m getting the GUID the same. So I did some digging and here is what I found.
The first thing I noticed that the time on the VM was the same date and time as when the snapshot was taken so the time does not syncronize.
7766DDFF-3461-438D-9B15-F23D4129AB43 (Time Created 4/10/2011 2:09:11 PM) (Time Modified 4/10/2011 2:10:36 PM)
7766DDFF-3461-438D-9B15-F23D4129AB43 (Time Created 4/10/2011 2:07:59 PM) (Time Modified 4/10/2011 2:07:59 PM)
As you can see I reverted the snapshot and the GUID is the same on both but does have different time like minute or so. What you need to do is this.
1. Configure timezone for the VM and create a BAT file that includes "w32tm /resync". Reboot the computer and create a new snapshot. Before you create a new sequenced application you can run the bat file and see if the date/time does syncronize. It is a possiblity that the computer needs a restart after the syncronization, you will problably see that in the sequencing wizard, so it is recomended to reboot the machine first. After this I get a new GUID as you can see and a new date time.
04E7BC0C-4F05-42C8-AFA5-011963BC52F2 (Time Created 4/19/2011 1:33:01 PM) (Time Modified 4/19/2011 1:34:26 PM)
Hope this helps.