Was just playing a pvp matchm using Malphite. The last fight I was in was with Warwick as my teammate using hit ultimate on Kayle, then after the ultimate I come in with mine. My W and E were used as well. Kayle died and I used B to go back and heal up and this is when the lock up on the move occured.
I could use my keys and mouse freely but I couldn't use right clik to move and my R was no longer on cool down but couldnt be used. My items had a glitch on the Ninja Tabi's, they had a 5 or 6 color rainbow square in the slot, rather then the boot graphic. When I opened up the trade window and moused over the Ninja Tabi slot it said "graphic_item_description_2002".
I tried to restart my client, after two attempts w/o success on taking care of the problem I did a full reboot of my computer. Still no luck and sadly caused my team to play short handed for the rest of the game. I have played new games since and have no problems.
Items I had at the time: Dorans Shield, Ninja Tabi,x4 heal pots, Heart of Gold, Philo Stone, Chain Vest.