The lazzerette cover is not a known leak problem. I would be surprised if  
water is coming in thru it. The lip for the Lazz hatch is 3/4" if I remember  
correctly. Best chance of leaks are still the two drain hoses. If they become  
clogged, it's possible that water could get into the Laz around the cover. It  
might also have something to do with how your boat is weighted. You didn't  
mention if it is in the water or on the trailer. If in the water, most R22's are 
 front heavy and will pond some water at the front of the seats. However, if 
you  are stern heavy, it's possible water could get under the lazz cover.
Then there's the option of actually crawling into the lazz with a  flashlight 
and have someone hose the area down. It's big enough for most owners  to fit 
in comfortably. :)
 
Rummy