As default BOINC will cache some WUs but not a whole lot. To increase the amount of WUs cached:
Sign in here
, click on "View or edit general preferences", click on "Edit preferences", and edit the "Connect to network about every" field, make it however many days worth of WUs you want to have cached (7 days should be good), click the "update properties" button. Open up your BOINC client (on each computer), click the projects tab, right click on seti@home, left click on update.