Has anyone ever used the TXB0101 level shifting IC's to interface between an Arduino and Telit GE865? I serially connecting through a TXB0101 (single channel bidirectional logic level shifter) and a TXB0106 (six channel) and for some reason the communication from the Telit (2.8v) to the Arduino (5v) is extremely noisy...to the point that the data is garbled. The Arduino(5v) Tx to Telit (2.8v) is very clean but as soon as I connect the other signal it all goes to hell. I was originally using the Sparkfun logic level breakout pcbs which worked well but I wanted to try the other IC's because they have an OE that I would like have controll over to HiZ the serial port. Should I be using pull up resistors maybe? Any help would be appreciated.