bed temperature slider not working in repetier v103 (no replies)

Hello, after connecting a 160mm heated bed on my kossel mini the temp.slider is not responding.
Tempsensor is working (tested with cup hot coffee on bed and with ice )
When temperature is reached, D08 shuts off. And on again when colder. So this is correct.
But when I put a value in the inputbox behind the slider , say 95, it flips back to 0.
When I slide the bedtemp slider, nothing changes in the input box. (extruder slider and other sliders work normally)

Anybody an idea? I am not an elektronics specialist... Working with mega2560 and ramps1.4 ....
Any help is welcome!

Have a nice day!
Willem de Zeeuw ( dot nl)