i also ran into this problem. 

if i can remember correctly, the cause was something along the lines of:

the pd samplerate needs to be set before the delayline code is initiated.  if pd is run in gui mode, then the gui initialization forces the order correctly.

however, when run in -nogui mode, the samplerate is set after the delayline code, and the calculation for the delayline is set with samplerate = 0

our hack was just to tweak the pd code to have a hardcoded samplerate.