I had an IRS lien placed on me in 1996, how long can it last?

My 2006 tax return showed a small refund due me, but when I got the check the IRS had withheld some of the money. This would have been the 1st time since the lien was placed that I was due more than a few dollars back. The original lien was then, and more so now, more than I'll ever be able to pay back. The money was a mere pittance to what I owe, but was very important to me. Is this what I'm to expect the rest of my life? I am a good person who made a regretable mistake years ago. It is severely depressing to think that this will be haunting me to my grave.