s2c programmable, clock speed configuration

I have a set of programmable s2c units that I am using in battery powered applications. I want to reduce the clockspeed of the CPU to reduce power consumption when not in sleep mode.

To test, I have an s2c on a XBIB communication user the “Transmit Basic Frames” program included with CodeWarrior.

The program runs as expected when the XBee is configured to run at 48Mhz, however whenever I try to run at one of the other two clockspeeds (16 and 36) the xbee takes forever to “boot” (~25-30 seconds at 16Mhz) and never appears to transmit a packet to the network coordinator.

Any thoughts on what I could be doing wrong? I did play around with the UART speeds both from within config.xml and the “BD” parameter in XCTU but nothing I do seems to help the situation.

Is it normal for these boards to take so long to load when at a reduced frequency? How should I be configuring the radio/uart/ etc for this to work?