HELP! Single widget loosing DMX!

Dear HES guys,
HOG3 Single DMX widget running under HOG 4PC starts loosing DMX output. First 5-8 minutes it works properly and then fixtures missing DMX. When disconnect widget and then connect it again and restart HOG 4PC after 10 minutes at list it will start working but in 5 minutes DMX loosing again. Strange, but everything around looks like nothing happens: Windows OS still recognize it as widget, LEDs on rear side remains turned on, DP8000 settings menu shows it connected and when press Beacon button LEDs flashs. Even the DMX window shows the signal but in fact there's no DMX on fixtures.
PLEASE, DO NOT SAY it's up to DMX line or fixtures - when another console connected all works properly.
I have already tried to change USB cabel and even the laptop - nothing changes. What's wrong?