spell casting bar sometimes missing

[Thander]

Sometimes I don't watch the lag bar and just jam the spell key. The casting bar seems to disappear sometimes when I do this. Also if I cast a spell and immediately it gets pushed back, the casting bar seems to disappear for a short time. It seems like maybe the push back causes the casting time to go negative and nUI doesn't know what to do except hide the bar until it goes back to positive. The default casting bar doesn't seem to have these problems.