3CX sets up all extensions by default to only have 1 line, regardless of the phone type. Our Cisco SPA504g phones needed to accept multiple calls for the operators. After doing some research and talking with 3CX, I found that it was an easy fix. 

Recently, I was issued a new Windows Phone 7.  Being the owner of one previously, I was already familiar with the OS and had a Windows Live ID that I entered when the sales rep asked me.  The phone was just out of the box, and as soon as I entered my information, the battery died.  After attaching it to the A/C adapter, the phone came on and acted the way I expected it to with no additional setup questions.