Using SM mode 4 the XBeenever seems to wake up

I'm brand new at this and haven't even gotten to having XBees talk to one another. I'm just experimenting with cyclic sleep mode ST4 and I'm probably not understanding something because once the XBee goes to sleep it never seems to wake up and check for data.

My init string is this:
Wireless.println("ATID5555,CE0,PL0,SM4,SP64,ST5000,SPGT3E8,RO3,CN");

Now to me that says go to sleep after 16 seconds but wake up every 1000 ms and check for data.

Once I leave it long enough for it to go to sleep I can't get it back into command mode in code. Reseting the Leonardo does no good, it'll only respond to the +++ after a cold boot and even then it's not every time.

Forgot to say, Xbee series 1

If I set SM0 it works fine forever.

What am I missing?

Hmm. Now it's working as expected. Must have had something messed up and fixed it without knowing it.

Edit: No it's not, somehow I slipped a SM0 at the end of the string. Removed it so it's really SM4 at the end of command mode and it's back to not responding at all.