The amount of gasket goo applied in the pictures is a bit excessive, however it is required to seal the rubber half circle areas.
The gasket goo is supposed to be cleaned off and reapplied every time the cover is removed.
If the leak is from this area you can probably just clean off the crappy old stuff and apply some good quality new goo.
I have some spare at home if you want to give it a go.
Cheers
Shiney