Karthus - Gamebreaking bug ruining viability (RED POST PLEASE!)

This has been neglected for almost the entire season 4 now. No, it is not a buff display bug. Please, can a Rioter help us Karthus players out? :/

[GAMEPLAY] Karthus - Triple cooldown for no apparent reason

Pretty straightforward; his passive is horrendously bugged. Usually, the 2nd Q (lay waste) in your passive takes 2 to 3 times as long to activate. When you consider that you usually have about 2 to 3 seconds to hit them before they escape your passive, it effectively makes you sit there doing nothing until your opponent has walked out of range. This happens all the time.

Die Press q Press q again Note that nothing happens at all, no matter how much you spam q, within or outside of his range

It might have something to do with the way his passive roots him in place.

Also: Apparently the window to use your ultimate during your passive is sometimes reduced randomly to as little as one second, rather than the initial four. I've not noticed this myself but I've seen others complain about it.

http://leaguehappens.gr/wp-content/uploads/2014/05/passive.jpg

^ Example of what it looks like while spamming the 2nd q (notice that nothing is happening at all.)