What can we do to put down a call with a Cisco 7921g?

[raul.wamba]

Hi everybody,

we have some cisco 7921g phones in my enterprise and we are not able to put down a call when someone´s calling. When we press the red button (as you do in a mobile phone) it simply stops ringing and blinking, like if you are in a NoMlsta mode.

Do you have any idea?

Thanks a lot

[raul.wamba]

Just one thing, the NoMlsta mode it´s the same as DND mode.

Tnaks a lot in advance