Yes, I have tried that (also tweaking inter-key delay with no success). Delay of 0 doesn't even work.
It is just a really bad IR design by Nyco. I have programmed my Harmony for over 25 devices (16 at a time) and it has worked great for all except the Nyco.
Note: You can get Logitech support to remove key repeating from the the menu, select and direction keys (Remove Hold KEY) and that will stop the extra key travel while navigating. But if you use the remote to browse huge libraries of music/video/pic files, no key repeat on key hold is kind of tough.