Thanks Harebrain-you've been a great help.I was just crossing off all the agents who said that so you've opened up a whole new world of possibilities.
After finally finding an agent who's crazy about my MS (6 years in) I am despairing. She loved it but needed some fairly painless revisions to be made. I procrastinated for a a few months, then finally got down to it. I had left it too late though. She left the agency three months ago to set up a self-publishing company. I shall send it to her replacement at the agency but I am kicking myself so to all of you out there, if you have a bite don't let it get away. It's a hard lesson to learn.