After casting Profundity, next spell Cast Bar disappears

[km0s]

Platform: Windows
ISP: Time Warner Cable
Type of Internet Connection: CATV
Internet Connection Speed: 15Mbps
Date & Time: July 23, 2011 0333 UTC
Frequency: Repeatable
Character Name: Karleigh Edelweiss
Race: Miqo'te
World: Gysahl
Class/Skill Rank: Conjurer/11
Physical Level: 8
Area and Coordinates: Western La Noscea [17, 23]
Party or Solo: Solo
NPC Name: N/A
Monster Name: Plains Rat
In-Game Time: 4:30
Steps:

1. Cast Profundity on myself.
2. Engage combat with Plains Rat.
3. Cast Fire. (Consuming Profundity Effect)
4. Observe cast bar momentarily appear and then immediately disappear.
5. {Cast Fire.}
6. {Observe cast bar full duration.}
7. End Combat.