I just wanted to put this here in case someone else has the problem.
We had a software upgrade on our data switches last night.
When the users came in, their 5560 IP turrets were sitting at waiting for DHCP.
Putting the phones in teleworker mode (my usual fix for such things) did not resolve the problem.
We traced the problem to the DHCP ping packet in the switch.
The fix is to enter the command in the cisco "ip dhcp ping packet 0"
The full explanation for the fix can be found
https://community.cisco.com/t5/switching/the-dhcp-database-could-not-be-locked-please-retry-the-command/td-p/1661093Ralph