If you touch it with a tool, warranty is void. I'd send it back in again with a more detailed description of the event (if that's possible) including temperatures, riding condition, any jumps you may have come across, etc. That way they'll have a better picture. When "they said that there might be a slight plastic sliver that might of be causing the sticking," what they meant is that they have no idea.
If I remember correctly, your negative "spv" valve or whatever they call it needs to be at least 40 or so psi. But, when you air up the negative valve it adds to your positive so start low. You might just put the same amount in both, given that you have a negative valve, I can't remember what that fork looks like... If the negative chamber is too low, it'll just stay locked up and will only un-lock with a big bump. Kinda like the X-series Fox forks with the inertia valve. Or the brain shock. It's really just an inertia valve. Pretty simple construction but has to be made with high tolerances and doesn't work when it wears out.
In that case, other idea I could offer is that the inertia valve is sticking. If the shaft it glides on is worn it will jam up making it feel like it'll never un-lock. In that case you'll need a new SPV damper for this fork. You have to test it on all sides since the shaft only wears on one side and you can't see it since the valve is in the way. At least that's what my brain is telling me. I haven't looked at one up close in like three years!
So if you take it apart, that's what I'd look for...
JP
