The debt collector originally levied my bank account, and starting this year (2010) they are garnishing 25% of my wages. Is it legal for them to still levie my acounts?

Yes,with a judgement they can levy your wages or bank accounts until the judgement is satsitfied. But be aware there is always interest added on so the original amount will be more.

As DownUnder said, they certainly can ONCE they have obtained a judgement against you. Where you not aware they had filed suit against you and won a judgement?

If you were totally unaware of the suit, you MAY be able to get the levies and garnishment orders vacated on grounds of improper service. But they will just reserve you and take you back to court.