Sims 3 Island paradise ....freezing issue

your not missing out any anything island paradise has lag and routing issues first try the reset all sims cheat in case some are stick somewhere you can't see

to reset all sims ctrl+shift+c hold all 3 together in the menu bar that appears at the top of the screen type in resetsim *   (inculding the * hit enter ) this will reset all sims including your own make sure your own aren't doing anything important cancel their acton q

and see here for more tips from crin 

http://answers.ea.com/t5/The-Sims-3/Variety-of-glitches-occurring-since-installing-Island-Paradise/m-p/2118385/highlight/true#M122387