Incorrect Offhand Thac0 While Dual Wielding (WPO 124)

[aruru99]

With 1 point put into two weapon fighting style, my offhand thac0 is +11 rather than +5(+6? is the 1 thac0 penalty from using 2 daggers supposed to apply to both main and offhand? because currently it does). When I put a 2nd point into two weapon fighting style, the main and offhand thac0 penalty goes to +1/+1. This is with only component 124 wpo fighting style overhaul installed on vanilla 2.6 BGEE, no other mods.