Hi Brenden,
On my custom code I do to, however the ShoppingCartItemSelector is an e-commerce module control, and IsLiveSite is used across it.
Strangely I don't think I have this behaviour on the Web Site Project version of the same site, so I suspect this may be somehow related to being a Web Application Project?
To clarify this was a brand new install using application project that we then imported the site from an export of the web site project via the CMS.
Cheers,
P.