I can place calls but I am not able to receive them, what is wrong?
Problem:
If you can make calls but not receive them and the softphone is correctly registering with the sip proxy, your installation might have not been entirely completed.
Solution:
Make sure that every time you install any softphone in Windows 200 or Windows XP you are logged on as the computer Administrator, which will give you full control NTFS permission to the folders needed to access during the installation.
Do not install the softphone using the "Run As" option; this option is not meant for installations but to run a program.
If you use this (Run As) option you might not get an error message but due to insufficient NTFS permissions for some folders some components wont be installed causing this application to fail.