I just bought 2 brand new knives. A manix 2 lightweight for myself and a Byrd crossbill as a gift for someone. The lockback on the crossbill is extremely stiff. Not from friction but from very high spring tension. It's actually impossible to disengage the lock by hand. We have been having to press the lock onto the corner of a table or something to get it depressed. It doesn't seem like it getting much better. But to close it is such a task it's only been opened a few times. Will this loosen up at all or should I return it? Manix on the other hand is great. Thanks.