Karthus dying by Lissandra freezing bug

None of my friends believe me, but when Lissandra freezes me when I'm as karthus, and I die, I can't use my skills. It won't let me use it. All my skills are all locked up and it's impossible for me to use any skills when dead, which should not do this. So I gotta sit and wait to respawn...It's like when she freezes me then when I die while frozen, I'm still frozen.