Compatibility issues openhab and oracle jre 1.8


I have compatibility issues regarding openhab and oracle jre 1.8. No matter if using openhab 1.7.1 or 1.8.1 when using oracle 1.8 jre in certain contexts sendCommand(item, OFF) does not work. I was told to use item.sendCommand(OFF) and indead this is a workaround.

Going on testing I found that scheduled code is not working as well. Here is a code snippet:

rule "Küchenheizung Timer"
                Item kitchenHeating changed to ON
                logInfo("rules", "Küchenheizung ein")
                heatingTimer = createTimer(now.plusMinutes(10)) [|
                        logInfo("powersave", "Küchenheizung aus.")

Code is not scheduled and there is no error message. I would be grateful if anyone knew a workaround for this problem as well.
Unfortunately I cannot downgrade to oracle jre 1.7 because I need fritztr064 addon that works with oracle jre 1.8 only.

Best regards