Well, if I remember correctly, Jesus did say that whoever marries her who is divorced commits adultery...
Which verse are you referring to? I believe that when looked in context Jesus is speaking of a woman who has not been properly divorced, who has been divorced for frivolous reasons, i.e. her old marriage was never really broken. And, Jesus gave an exception for fornication.
Matthew 19:9 And I say unto you, Whosoever shall put away his wife, except it be for fornication, and shall marry another, committeth adultery: and whoso marrieth her which is put away doth commit adultery.
A man who puts away his wife for fornication and marries another does not commit adultery. Logically the same should apply to a woman divorcing a fornicating husband.
EDIT:1 Corinthians 7:10-11 (NIV)
"To the married I give this command (not I, but the Lord): A wife must not separate from her husband. But if she does, she must remain unmarried or else be reconciled to her husband. And a husband must not divorce his wife. "
But, if we look at a bigger chunk of the passage,
1 Corinthians 7:10-16 And unto the married I command, yet not I, but the Lord, Let not the wife depart from her husband: But and if she depart, let her remain unmarried, or be reconciled to her husband: and let not the husband put away his wife. But to the rest speak I, not the Lord: If any brother hath a wife that believeth not, and she be pleased to dwell with him, let him not put her away. And the woman which hath an husband that believeth not, and if he be pleased to dwell with her, let her not leave him. For the unbelieving husband is sanctified by the wife, and the unbelieving wife is sanctified by the husband: else were your children unclean; but now are they holy. But if the unbelieving depart, let him depart. A brother or a sister is not under bondage in such cases: but God hath called us to peace. For what knowest thou, O wife, whether thou shalt save thy husband? or how knowest thou, O man, whether thou shalt save thy wife?
I believe Paul first gives instructions about a woman leaving her husband for no good reason, or insufficient reason. She needs to reconcile with her husband. If she does not, she must remain unmarried, for she is still bound to her husband in marriage for she forsook her marriage covenant for no good reason.
Later on, in v15 Paul gets to someone with a legitimate reason; he or she has been abandoned by an unbelieving spouse who will not live with a christian. And Paul says there is no more bondage for the abandoned spouse.