seems to have done the trick
took the lcd unit off the bike, cracked the back open as it seemed to be sealed with glue. bit scary but if it didn't work i think id have hed to buy a new one sooner rather than latter.
i then used silicon sealent around the inside of the screen. and resealed the back with silicone aswell.
seemed to take a few days to fully dry out as i got a bit of mist inside for a day or two.
but since then ive been in some stunning downpours, snow aswell. and as of yet the lcd has been working fine