Isn't the Dodge Bonus lost as well? Yes; Dex, Dodge and Tumble are associated AC types
Proposed description, (more like the Game Manual version and correct uncanny dodge to invisible attackers)
Flat-Footed
When you are caught off-guard, you are considered flat-footed. When flat-footed, you do not add your Dexterity bonus (if any) to your Armor Class and you are susceptible to a rogue’s deadly Sneak Attack. The Uncanny Dodge extraordinary ability allows the barbarian and rogue classes to avoid losing their Dexterity bonus to AC when they are caught flat-footed by invisible attackers
You are likely to be caught flat-footed when: (effects may vary with condition)
- You are performing a non-combat task.
- Attacked prior to the Initiative check.
- Attacked by an undetected opponent.
- Stunned, paralysed or asleep.
Gameplay: When caught flat-footed you lose all Dexterity, Dodge and Tumble modifiers as well as unable to make attacks of opportunity, defensive rolls or deflect arrows. For those with negative modifiers, this may improve their AC when caught flat-footed. Due to perception and the subsequent combat, it is likely only the first ranged attack of any encounter will be able to attack prior to the Initiative check.
Note: When flat-footed cannot make attacks of opportunity, defensive rolls or deflect arrows. (This is a NWN condition and not confirmed for NWN2). Further more; hostile targets that revert from a combat stance to a relaxed state. Will again become flat-footed and susceptible to an Assassin's Paralysis check.