Thank you sir!! I’ve been dealing with the same problem on a Cisco 7821 phone. Although I believe the OP (hariskar) has an SPA series phone based on this thread, I can confirm that your solution also works on newer Cisco phones running Multiplatform Firmware (MPP) like my 7821. Presumably, this means it would probably also work across the entire 78xx, 68xx and 88xx lines (with MPP firmware). Cisco apparently carried over this bug from the now-discontinued SPA line into their newer (current) enterprise lines.
-cinergi