Index page never cached but rest of site is?

Non cache problem on website

[agent10]

I have a site page 1 for months on yahoo for a good financial term. During the current update we dropped to page 3 and now gone complately although still in serps for other search terms.

However for months our index page never seems to have been cached yet we include new pages and update our home page most days. On looking at all our internal pages they say they are cached but then on further investigation 90% of these do not show any cached results.

The site is cached by google and msn at least every week, might I have a problem with our site for yahoo. It didn't really concvern me when we were well positioned but now feel having fallen from the serps that maybe we have a problem with yahoo seeing our site correctly.

Any help would be great.