When running JTDX (version rc155 with the ic-705 supported) and the Icom Remote Utility I kept getting annoying errors from HamLib which made it unusable.
Hamlib error: Protocol error while getting current VFO frequency
Hamlib error: Command rejected by the rig while getting current mode
It seems that if you turn OFF the CI-V Transceive option in the Connectors->CI-V menu this fixes the issue. All problems went away, however I did need to restart the Icom Remote Utility.
I assume Hamlib wasn’t handling the returned ci-v commands with the ci-v transceive setting enabled. This may be the case on all Icom radios, not sure, however it is a default setting on the ic-705.