Disco II TD5 with leaking front sunroof

I have a 2000 Disco II TD5 that has developed a leaking front sun roof. I took the sunroof off in the summer to try and fix it but it does not seem to have done the job. I removed the glass, took the rubber seal out and cleaned in fully. I then sat it back on a bead of silicon sealer. Then it rained again ! - the leak does not seem to happen if i park it on the road with a camber - with driver side being high ? - has anybody got any ideas ?

Have a look at this post, it should give you some details -
http://www.landyzone.co.uk/lz/f8/disco-gs-sunroof-drains-36370.html?highlight=sunroof