[TomMcIn]

I have an applescript that formats a Pages document. Normally I start with the Pages application on the System Disk and all works well. On occasion the Applescript starts using a backup copy of Pages on another disk and the script fails because this copy of Pages does not have a document to format. Is there some way to force the Tell command to reference an application on a specific disk?

The tell command used is tell application "Pages"

[P]

No, not easily. I suggest that you make a zip archive of the backup application so the script only has one app to choose from.

[TomMcIn]

The wrong copy is being picked up from a copy of my operating system disk I made before upgrading to Lion. Will Zip that copy. Also have a disk partition that keeps a copy of my system disk that gets updated/cloned every two days. Could add a script to zip the copy if that copy becomes a problem.

[pottymouth]

Originally Posted by TomMcIn 

The wrong copy is being picked up from a copy of my operating system disk I made before upgrading to Lion. Will Zip that copy. Also have a disk partition that keeps a copy of my system disk that gets updated/cloned every two days. Could add a script to zip the copy if that copy becomes a problem.

A couple notes:
Do you see this problem if Pages is already running? Or only when you run the script without pages running?
Any particular reason youaren't using Time Machine for your backups? TM backs up to a disk image, so you wouldn't have this problem.
A backup to a different partition isn't going to help you one bit when the disk fails...or maybe that's not really what you meant.

[TomMcIn]

In all the cases, I had my main copy of Pages running on a document I wanted the script to reformat. Instead, sometime after each reboot, the script would run a copy of Pages from a system disk I had created and tested, just prior to updating my main system disk to Lion.
I also run a copy of TimeMachine, just use the extra backups as insurance. I tend to consider TimeMachine as a way of getting old versions of a document.
I have three physical disks. Time Machine and the backup partitions are kept on separate disks from the main system and document disks. If a disk fails, the backups are on another disk.

After zipping the copy of Pages on the preLion backup, I have not seen the problem again.