I recently purchased a new Motorola V400 phone on eBay.  When I inserted  
my SIM card and turned the phone on, I received a message telling me to  
"Insert SIM".  After playing around with the phone some, I was able to get  
my SIM card to read by making sure the battery was pressing tight against  
the SIM card.  I put some tape on the battery to make sure that the SIM  
card was being pressed against the contacts when the case was closed.  
This worked initially, but after a few minutes, the phone would shut off  
and then pop up with the "Insert SIM" prompt.  Do I have a phone with an  
isolated defect, or have others experienced this problem as well?

Thanks.