Wrong enhanced duration on "Jigs" abilities for Dancer

Platform: PC Windows 7 and Xbox360
ISP: Alice
Type of Internet Connection: DSL
Internet Connection Speed: 7mbps (downstream), 512kbps (upstream)
Date & Time: 23/07/2015 20:30 GMT+1 (DST)
Frequency: Always
Character Name: Sechs
Race: Galka
World: Asura
Main Job: Dancer, lv99
Support Job: Warrior
Area and Coordinates: Anywhere
Party or Solo: Party and Solo
NPC Name: None
Monster Name: None
Steps:
1. Equip Horos Tights +1 in the legs slot (enhances "Jigs" duration by 45%)
2. Equip Maxixi Shoes +1 in the feet slot (enhances "Jigs" duration by 40%)
3. Use any "Jigs" ability
4. Notice that the duration gets enhanced by only 50% and not 85%.