Sleep->Hibernate transition problem (BIOS Password)

This applies to a Dell M1330 (original series) running Windows Vista. I didn't find the issue documented elsewhere. I presume/hope it is resolved for later BIOS versions and Operating System versions... but this info may still help anyone continuing to run their M1330 (Seems the lounge is closed so I can't post there)

I was perplexed why the battery would drain completely after maybe 4-5 days of closing the lid. I had it configured for Hybrid sleep... shutting the lid would put it into Sleep, and then a few hours later, if still sleeping, it was set to go to Hibernation... and I figured then it should no longer be using power.
I looked into a lot of things like minimizing devices capable of Wake on LAN etc.

As this laptop is used infrequently the battery was often getting drained and I think damaged.

After a lot of playing and reading on the web I thought to try setting it to sleep in 1 minute, and got to Hibernate after 2 further minutes... so I could observe the Sleep to Hibernate transition.

The answer was easily observed... after the 2 minutes of Sleep state it woke up and prompted for the BIOS password!
If I didn't provide it... it waited 10 minutes for the password and then went back into the Sleep state... continuing to drain batteries. I also had the Critical Battery Action to go to Hibernate (not Shutdown)... so the result is total draining of the battery.

So the solution was to go into BIOS and change
Security - Password Bypass - Resume Bypass
(At some point I had set it to prompt for the BIOS and Hard Disk passwords whenever it was started...even from Resume or reboot)

This does reduce the security somewhat, but is far better than continually picking up a drained laptop, losing work in progress, and having to buy new batteries.