1.03 contains a few small changes and fixes some small bugs from the 1.0.1 version but most users will not notice the difference.
Be aware that in version 1.0.3 if you put the Core into sleep mode all logs will be erased (except locked ones!!)
If you have any specific questions about a bug that you may have found I would be happy to answer them -
eg. Q. "My button tones disappeared"
A. This can be solved by removing and reinserting the battery. It has been fixed in SW 1.0.3, athough this bug is pretty hard to find and it will never happen to 99% of users.