It looks like you are hitting this bug, have a look;
CSCsg87192 Bug Details
Headline 79x1 phone delay to display system message after deactivate DND
First Found-in Version 8.0(3)
First Fixed-in Version 8.3(0.12), 8.2(1.5)
79x1 (7961 and 7941) with cme 4.0.3 delay around 30 seconds to display system message after user deactivate Do Not Disturb via pressing softkey.
Customer activate DND by pressing the DND softkey and the screen changes to "DND" instead of system message which is fine, however, when customer deactivate it...it takes approximately 30 seconds for the DND to change back to the system message.
The problem is only with SCCP41.8-0-4ES4-0-1S and SCCP11.8-0-4SR1S, and NOT seen on earlier firmware like TERM41.7-0-3-0S. It is not seen on 7940/7960 as well.
use firmware TERM41.7-0-3-0S
Here are 3 other threads where people were having the same trouble.
I'm not able to access my old voice mail messages all of a sudden. The recording says something like 'the message is currently not available'. This has never happened before in all the years I have been using this system. I have t...