I have a slight problem with yahoo crawlers as it cannot index all the pages. I have page www.domain.com/subfolder/home.html 301 redirected to www.domain.com/subfolder/ so it looks better but for some reason yahoo cannot crawl and cache www.domain.com/subfolder/, although other pages are indexed and google and bing have no problem. How can I make yahoo index and cache www.domain.com/subfolder/? Thank you for your help.
You can submit the URL to Yahoo. Better still, submit your sitemap to Yahoo. Or you can ping yahoo with this pinging tool. I think all of these are a largely waste of time though, but they can't hurt. Just be patient and everything will get crawled by itself, provided your subdirectory is linked correctly from somewhere on your site (best if it's linked from your home page). But Yahoo is on it's way out! Yahoo Search will be internally replaced by Bing within a year. Worry about Bing, not Yahoo!
If your website contains a lot of pages and still Yahoo does not index most of them, you are recommended to work on your website's internal linking structure. For example, create some static HTML made sitemap pages and add links to your other web sections.