need help with Yahoo & MSN

I would really appreciate some good advice because I am totally lost here. Our website: http://www.escaperental.com was launched about 8 months ago and up to 3 months ago it had quite a good ranking in Yahoo and MSN. And then it totally disappeared.... The Inktomi subscription has not expired yet (and even if it had, we have some other websites that kept great ranking even after the subscrption expired).

Right now the website has only ranking in Google, ranking in all other search engines disappeared.
Ranking in Google is not too bad:
- vacation rentals by owner #4
- vacation rental homes #6
- vacation home rentals #7
- condo rentals #4

What can we do to get the ranking back in Yahoo. Any suggestion greatly appreciated.