I upgraded a few 3845's from 12.4(12) to 12.4(15)T5. A few upgrades show that the Gig0/0 interface that has a LX SFP in it does not come up. Regardless if you bounce or reseat. We downgraded the code back to the original and the link comes up. Can't find any bugs, and cases have not proven to be successful. You do see log messages of the GBIC being inserted and removed. I have found some doc on cisco being stricter on the supported SFP's. Has anyone seen similar issues? Even seen this on 3750 switches.
I have this problem too.