I had the same problem, I tried to reinstall too but nothing changed... :/ If someone can find a solution... BTW I asked someone in Japan to find me a DC2 Sourcenext version, I'd like to try it. Seems to be so much better than PC !! That version is pretty hard to find.
I just found Unopened Sourcenext PC version. 4,000 Yen. Ill buy in 1 week ;) Hope still be in shop. PogChamp
Updates on the sourcenext version? I'm also getting the same problem but reinstalling doesn't fix anything for me.
EDIT: Found a fix, I used Rivatuner D3Doverrider and forced VSync.
Reviving the old thread but I've used the Rivatuner D3Doverrider, forcing VSync and triple buffering and that kiiinda fixed my input problem, I can sometimes start the game (Mashing enter hoping I can start the game, it doesn't even show the start/load/options menu), but I'm getting very low FPS, making the game unplayable. Does someone know if this is solvable, and how?