MDeviney,
Check out that link I provided in my above post.
Colorado is a bit complicated due to a "home rule" provision in the state's constitution. As best I can explain it, from my understanding, "home rule" allows cities to control all law making on issues primarily of local concern (as opposed to the typical idea that Federal can preempt state, and state can preempt local law).
So, anyway, based on "home rule" Denver argued in court (in 2003) that their more restrictive laws (on CCW, Assault weapons, open carry, etc) were permisible due to home rule... Essentially, they argued that these were matters of local concern.
The state argued that these were issues of statewide concern, and thus that home rule would not apply (that is, that the state had preemption power on this issue).
Judge Meyer made this rulling, and it was a split decision in favor of the state on some issues (concealed carry, carry in vehicles, etc) and in favor of Denver on some issues (open carry, assault weapons).
Personally, I'm not a fan of home rule. It makes for these types of ridiculous complications, and paves the way for too many pointless legal battles. I was also baffled by it when I first moved to Colorado, as my previous state had no such provision for allowing the city to overrule the state!
Be sure to read the link that I provided above... It pretty much spells out that court ruling!