I had exactly the same problem on my W reg 2000 laguna. I took out the hazard lights switch unplugged it and clean it and plugged it back in. The indicators then worked fine but if I pressed the hazard lights it was touch and go as to whether the hazards worked or the indicators!
I then bought a new switch with hazard button and with the door lock/unlock button on the same bit from ebay, it took a minute to replace and haven't had a problem since! hope this helps. Liz
Liz Brindley
April 2008