Having the same issue with IAP-92's. They are running the latest 6.4.2.6-4.1.1.10_51810.
The 103 is stuck in some degraded CLI state which makes it impossible to upgrade - even the GUI won't let me login. Needless to say we will start looking for a different vendor for AP remote deployments, these Instant APs are getting far too buggy to deal with. When you can't even add it to an existing group without breaking it, completely ridiculous.
Is this going to be the case for every upgrade moving forward with a mix of firmware/APs? One of the models will break until manually upgraded? Also, it would help if in the firmware download section you actually listed what the 103's use (Pegasus for anyone dealing with this headache).