Sundevil summed up. Inability to change back to DHCP from fixed IP, only after a few hundred tries.
I'm also a little unconvinced that this is a bug. AFAICS there are 3 scenarios:
1. It is a outright and easily reproduced bug and anyone trying to change a previously-assigned static IP address would encounter the same problem.
2. It is an edge case where there's some interaction of user, logger, network, router etc that provoked this particular experience, but which might be pretty difficult to reproduce outside of that specific network situation.
3. There's some other explanation not involving a bug.
This is the first time in 10 years of supporting the IP logger that I've come across any user having this degree of difficulty in trying to change an IP address (assuming that they're still on the right subnet), so I have my doubts that [1] is the explanation.
[2] is a possibility, but unless it's possible to reproduce what seems to be a pretty rare issue under test conditions in the development lab then how is anyone likely to be able to diagnose and fix the 'bug'?