Hi Carolyn,

This bug (below) manifested itself in exactly the same way you have experienced for our 3rd generation phones. 7941's and 7961's both had this type of random problem until the 8.2.x Firmware. The bug lists the problem as Answering calls only, but as I say we also had the same Handset issues. The chances are very good however that the problem is the second one I have listed below;

Looks like this Firmware bug continues to plague IP Phones;

Release Notes

Symptom:

Rarely a 7900 IP phone will get into a state where the speaker, headset, handset, or line buttons will not work to take the phone offhook. In this state the only way to go offhook will be to use the softkeys.

Conditions:

This has been seen in various Skinny phone loads up to and including 7.0(2)SR1. It is not dependant on CallManager version.

Workaround:

A simple IP phone reset will recover the phone.

Further Problem Description:

The root cause of this issue is not known at this time.

This problem will be further addressed in the 8.0 Skinny loads by adding more debugging to the IP phone console. If you suspect you have an IP phone in this state running an 8.0 load please do not reset the phone and contact TAC immediately.

CSCsc99161

Phone does not go offhook except via softkey.

http://www.cisco.com/pcgi-bin/Support/Bugtool/onebug.pl?bugid=CSCsc99161

This could also be a hardware problem with the Hookswitch. After deploying Cisco IP Phones for the last few years we (and many others) have found this to be the most common hardware problem. There is a "Best Practice" for cleaning the Hookswitch contacts (link below) that does work on occasion. Usually the phone has to be replaced/RMA'd.

Best?? Practices for Cleaning and Troubleshooting Cisco IP Phone Hookswitch

From this interesting Tech note;

http://www.cisco.com/en/US/products/hw/phones/ps379/products_tech_note09186a00801c0810.shtml

Hope this helps!

Rob