Input devices problem on gimp in unity

When I used gimp(6 and 7), I had some trouble in unity 3d.
I drew some strokes with brush, but it was missed sometimes. And I tried to use any tools, it was missed too.

I had believed that it's a problem of gimp, but it's not.
It worked well in Unity2D and Ubuntu Classic.

I think that it was input problem or it has some crashes in unity 3d.

I had a error massage in terminal.

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 (gimp:16188): Gimp-Tools-CRITICAL **: gimp_tool_oper_update: assertion `gimp_tool_control_is_active (tool->control) == FALSE' failed
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