Patch 1009 contains the following:

Optimized game content to reduce memory usage and improve loading times

Fixed acheivements that weren't working, 3 Map Achievements for KF-Bedlam, Dot of Doom, and Mr. Perky. Mr. Perky was appearing as though it had been reset(it was working behind the scenes, but the menu functionality was not working)

Fixed an exploit related to weapon dropping/selling in the Perks system(that people used heavily with the Medic Gun). This exploit could be used to buy a weapon on a discount and give it to someone else that would sell the weapon for a huge profit

Fixed errors in Perk Descriptions (such as the menu saying the level five Sharpshooter get Dual Handcannons, when he actually gets the Lever Action
Rifle)

Fixed exploits in maps Wyre and Bedlam