The DESC on the "Nimble ~ Gunslinger" special ability in the pfuc data set (pfuc_abilities.lst) includes the text for an unrelated class feature (bonus feats) at the end of it. The bonus to AC is also missing.
CATEGORY=Special Ability|Nimble ~ Gunslinger.MOD DESC:.CLEAR DESC:Starting at 2nd level, a gunslinger gains a +1 dodge bonus to AC while wearing light or no armor. Anything that causes the gunslinger to lose her Dexterity bonus to AC also causes the gunslinger to lose this dodge bonus. This bonus increases by +1 for every four levels beyond 2nd level (to a maximum of +5 at 20th level).
CATEGORY=Special Ability|Nimble ~ Gunslinger.MOD DEFINE:GunslingerACBonus|0 BONUS:VAR|GunslingerACBonus|min((GunslingerACLVL+2)/4,5) BONUS:COMBAT|AC|GunslingerACBonus|TYPE=Dodge|!PREEQUIP:1,TYPE=Armor.Heavy,TYPE=Armor.Medium
Looks like the AC bonus has been added to the latest version, but the description still contains the extraneous text about bonus feats.
Yes, the Bonus Feat is supposed to be another ability. Working on the fix. Will finish it tomorrow.