Combination of rough edges in the Ultra-lock's slot (in the liners) and the tendency of the edges of the D-bolt to get stuck makes this to be a difficult problem to solve. I tried 2 approaches. 1st is to use a fine grit sandpaper (wrapped around a small steel bar) and sandpaper the edges until smooth. The 2nd option is to smoothen out the dang edges of the D-bolt till there is no edges and it does not look like a D anymore. I usually advice doing both together.
I too feel the same way as razorburn. The construction of the Recon 1s are very solid with 5 strong bolts along the spine. The positioning of the lock-bar (when opened) means that it's very very strong in resisting cutting forces. In addition the almost 'closed' type construction where the blade encloses the lock means debris don't get in easy.
If they made a spear point with plain edge and with VG-10 (or VG-1 whatever it is) and sorted out the lock issues I'll be on that knife like ???-on-rice (can't remember the American phrase

). A 5 inch version with Titanium handles for SD wouldn't be too bad too.