photoshop cs2 problem

okay this is so odd but i now have photoshop cs2 on my computer and it LAGS so bad! ps7 never did but now it takes forever to do anything in cs2 because it lags for a minute and then its okay.

has this happened to anyone else? i know my computer is kinda old but i dont think there's THAT much difference between ps7 and cs2 is there? i even tried the beta for cs3 and it didn't lag like this