Octoprint resets when trying to move XY

hi Folks
i am running on a PI3 mobel B using versions 1.13.0 and 0.16.0 but seem to have a strange problem in that when i try to move X or Y directions the octoprint resets its self but nothing in the Z direction this works perfectly.
has anyone got any ideas on were to look for a solution in the way of do i take the manly route and hit it with a hammer or the more gentle approach of re-installation of system if necessary or track it down in the software (i am trying that route now but not succeding to date)

regards
Les