It appears that the first time someone comes into the store they are getting bad session id added to the url. I can only reproduce it if I totally clear the cache on my browser, etc.
I've noticed a big increase in the 404 error pages in analytics.
Examples of pages showing up:
http://www.buskerdoo.com/catalog/expansion-cd-mailer-123?osCsid=060edc0ef739f2f142c03e07bb83afc4.html
http://www.buskerdoo.com/catalog/cd-paper-sleeves-28?osCsid=9229e1adce8e50ab5500b4fa09b59942.html
http://www.buskerdoo.com/catalog/cardboard-cd-sleeves-136%3FosCsid%3Df876380ca20abf771f17070c4f22c394.html
Notice sometimes it's using a ? and other uses %.