Instant abilities got eaten if you press the key too fast

Windows version

This is indeed a game bug, so I am not going to post all information.
(my pc is i7 3770k,16g ram,hd7950, win7 x64)

This is how I did:
1.Cast a GCD ability (PLD Flash etc)
2.Cast an instant ability immediately, Rampart etc. (within 0.5s-1.5s after step 1)
3.Cast GCD ability (Flash) immediately again (within 0.1s-0.5s after step 2)

Now the instant ability will have a high chance get eaten (CD, but no buffer show up)


Edit:
I uploaded another video about this bug.this time I use mouse too,to demonstrate.
http://www.youtube.com/watch?v=t3p4wMxSs28

because the first video(http://www.youtube.com/edit?o=U&video_id=6NyIxyzrtaA ) also shows you another issue:
'An ability "sometimes is ready, sometimes not" bug.' :
http://www.youtube.com/watch?v=uLRXFmWGBLQ

I uploaded a Youtube video, to show you how to reproduce this bug
http://www.youtube.com/watch?v=6NyIxyzrtaA

In this example, I cast Flash & Foresight,
As you can see, the Foresight buffer got eaten (ability cool down,but has no effect).
Bug reproduction method: Cast a GCD ability & any instant ability in high speed.

Happening the same to me(PS3), it's really frustrating, especially when i use important CDs like infuriate, so please fix it asap

same thing happen to smn skill too