I've been experiencing the same problems through a number of dungeon runs. Today was at its worst, with Medica and Medica II not working for at least one casting of the spell. Stoneskin would get dropped and I'd have to cast it at least twice to get the actual effect. Sometimes I'd even cast Cure after that and have it canceled, try again, and get canceled a second time. During fights where I had to consume Morbol Fruit in Aurum Vale, when I tried to activate the fruit, I was stuck there for up to 5 seconds before the game let me even try to eat them. During this time combat was still going on and everyone's HP was fluctuating. This "lag" was even present when I was even running Wanderer's Palace with friends. Trying to activate switches caused me to get stuck there, waiting for the Yes/No prompt, and even longer to even see the progress bar. Then, during the second fight I started to cast Holy to help take care of the adds. I had to have cast Holy about 10 times during that fight and not only was my MP nearly full, but some of the adds weren't even being hurt by my spell, while others took the hits and died. That's when I REALLY noticed this problem. Until this gets fixed, I'm not touching dungeons.