Odd casting bar issue...

[Korereactor]

You probably have Umbral Ice active then you cast Fire III and Fire II immediatly after. When you cast fire 2 you get the shorter casttime from Umbral Ice even though you cast Fire III before.

Yeah, I get that, but what I'm seeing looks more like a glitch. The casting bar doesn't seem to be able to keep up so it just hangs half-way sometimes. I've seen it more than once now, and it does seem to happen on faster casting. All I'm saying is that the bar never makes it to the end - it looks like you were interrupted but you weren't.