Acronis TI Enterprise 9.1 - laptop Shuts Down

Have been using TI E Server 9.1 for quite some time on Laptop.

Back-ups incremental or full without issue. Just recently during the maual
backup process the laptop will power down.

Set ALL control panel power options to NEVER. External drive has plently of space. Incremental, full doesn't matter. Tried different external drive - same results.

Backup gets to like 30%, maybe as much as 60%, then POW, the laptop
shuts down cold. No message appears before the event.

Using XP Pro.

Any ideas?