Hey I have the same problem in reverse gear but only when the tranny gets hot. I posted in maintenance (
http://www.automotiveforums.com/vbulletin/t5715.html ) and T4 Primera gave me this link
http://www.se-r.net/transaxle_clutch/auto_lsd_info.htm
Try changing the fluid and the filter. If that does not work, try cleaning out all of the lines and the cooler which is housed in the bottom of the radiator. I believe that it is a fluid pressure problem. If none of the above works I'm going to clean out the reverse valve body.
Hope this helps,