Adding new products slows site down to a crawl-Collection of common programming errors

(We have an external app that allows us to upload products to CS2007 as well as build out product feeds for Amazon, etc.)

We have noticed lately that when products are added to our site, they will instantly show up as expected, but during this load phase our site will suffer performance issues (30+ sec page loads).  After loading products, 50-60 (1 at a time), the site is un-usable (1+ min page loads).  After an IIS restart the speed is back and everything is fine.

Can anyone shed any light on this?  Does introducing new products cause CS2007 to act differently, or am I looking at the wrong issue?