Studio 1555 HDD Password Frozen in bios

When I got my Studio 1555 in Dec 09, one of the first things I did was to set up a HDD password.  I did that on my Inspiron 6000, which I really miss, about 4 years ago as a precaution  for theft.  I never had any issues with the password, not even when the hdd crashed.  Dell sent me a new replacement and away I went.  On the Studio, I noticed a couple of days ago that it was starting up and going to the Windows login screen without pausing for a HDD password.  When I went into the bios tonight, noticed that the HDD password was frozen.  I cleared the user password and then the system administrator (?) passwords but still cannot do anything with the HDD password.  I can still access the harddrive and all my data without any problem but without using the HDD pasword which bothers me.  Another thing that concerns me is, at some point, am I going to get locked out of my harddrive.  I've been reading where that might be an issue.  I'm curious 1) why it changed all of a sudden with out any significant changes to the hardware or software or bios and 2) how can I get it back to the way it was ... functioning like I want it.  I'm really starting to regret getting this laptop and am thinking I should have stuck with the Inspiron, but I've purchased a lot of Dells at work and this is the first one I've had an issue with (go figure).  Any thoughts or suggestions would be appreciated ... I really dread calling Dell tech unless I have to.  It's definitely not what it used to be.  I know, I spent 5 years doing tech support for Dell.