Can imagent in OS X Mountain Lion be made to consume fewer resources? imagent is constantly consuming CPU cycles and a couple of GBs of "real memory" on my wife's MacBook Air since upgrading to OS X Mountain Lion. I believe this is part of the Messages app.

Is there anything that can be done to make it behave more acceptably, or is it just not practical to use on these devices?
Force Quit on the imagent process and then restarting the Messages app reduced memory consumption to a few MB instead.