Looks like there is an update to the Starter Site Release 2 you can still download it from MSDownload.

How to tell you have the right download?

I looked at the original release 2 and the file version for CommerceComponents.dll is 6.0.3863.0 and the update release 2 is 6.0.4109.0.

How to tell which files were updated?

Unfortunately, as far as I can tell there is no documentation on the bugs and which files were modified. You need to do a file diff on the code to identify changes :(.