Topic: boot properties of console

I got my CHB working with my iCreate.  I was trying to use the console (ttyAM0) to communicate with the iCreate.  I rigged a level changing circuit (3.3v on the CHB to 5v on the iCreate) and it can communicate with the iCreate.  However if I leave the circuit on the CHB and reboot, the CHB never boots up.

To sum up.  The CHB can communicate with the iCreate, but the circuit prevents the CHB from booting.  My question is why and is there a fix?