Ensure you are running the AnywhereUSB 3.60 drivers
For the AnywhereUSB 1.51 firmware, you must be running the AnywhereUSB 3.51 driver or newer.
Information from Digi Support site:
IMPORTANT: The v.1.51 firmware is incompatible with AnywhereUSB driver releases prior to v.3.51. Before updating to this v.1.51 firmware, ensure that all of the host computers are running the AnywhereUSB driver v.3.51 or newer.