My buddy and I both recently had our low profile valves replaced. They were both brand new Signature Series suits and neither of us knew any better before reading ScubaBoard. Both had problems with leaking even when "several" clicks closed. And no we weren't being squeezed to death. We had to bring them to our dealer and they were swaped out, but we were allowed to keep the old ones. Just last Wednesday 11/26/03, did a 3/4 day trip on the Spectre Boat out of Ventura, not a drop through the new high profile valve! Just for the record, the rest of the suits are absolutely perfect and we are happy with them in every other way.