addClass -- much slower in ie7... workaround?

addClass -- much slower in ie7... workaround?

addClass seems much slower in ie7. any way around this? (chrome: 0.002 seconds, IE7: 0.312 seconds)

It's not a big deal the first time, it's just annoying when you're doing it for different things. (example above was doing it on 254 elements)

if anyone knows a workaround, let me know.