32U4 and uext zigbee power problem

[c_arm]

Hi guys,
32U4 board doesn't provide enough current to power uext zigbee module.
When try to power up the board with zigbee attached to uext bus, the voltage drop down to 1.5volts.
Somebody have experienced this problem before

Thanks

[Lurch]

Are you sure you are driving D8 as OUTPUT high? Otherwise the 3,3V power on UEXT is turned off.