150mm N Shutter issue

[GeorgeTelis]

Today i received my new 150mm N lens. I am really pleased with the results and the lens is as sharp as it gets over its aperture range. Overall it is a wonderful lens.
There is a strange issue though, every time i open the camera or halfpress the shutter button (after 1-2 mines of leaving the camera without shooting) ,the shutter half closes.
If i take a picture or lock the mirror up then it gets back to normal. No issues with the exposures and all shutter timings seem to be correct.
What should i do?  

[Alex Maxim]

Doesn't sound normal. Service or return I guess. It might get worse.

Alex