I would add that hosting with "generic" sites like Yahoo could present you with additional problems.

E-Commerce is a serious undertaking - particularly when you start getting customer data and credit card data for gateway processing. The way the servers are set up (cURL, etc) often affects the ability of the software to perform.

If you are keen to start and run a proper e-commerce site, then you should look for a hosting company that understands (in our case) zencart, and who ensures their systems are set up for it.