Google against Yahoo! eCommerce Sites?

Does Google penalize websites using Yahoo! eCommerce programs?

[Cole WebMarketing]

Have a new client that currently uses a Yahoo! eCommerce packages for their website. They were well ranked at Google before the Florida update in Nov. 2004 and now are nowhere to be found.
Question # 1: I wonder if Google is penalizing sites that are Yahoo! clients?
Question # 2: This same client looking for an alternative to what Yahoo! offers. They have a 400 or so products and want a very user friendly system for managing their eCom. program. Any suggestions? Thanks.

[your_store]

I would definitely say Florida helped Yahoo! Stores more than it hurt them. The number of SERPS I had w/ 3+ entries in the top 10 from the same store jumped dramiticaly. It really seemed Google had disabled the duplicate filter for the various ystore domains.

I also have a lot of luck piggybacking on the strength of another listing on the shop.yahoo domain, getting an easy indented listing.

As for an alternative to Yahoo!, I can't really help you there. When we finally move off, I'll be building our system from the ground up.