Does it ever start again, does OTM stop responding, can you do anything else in OTM, can you do anything else on the PC? Does it finish the retreive and stop when it is writing to OTM?
depending on your answer, problem could be with ethernet link/hub/etc, or PC/OTMsoftware/etc
What if you just retreive a card at a time - same problem?
What if you reteive just one phone?