The short answer is, "Yes." Any encryption can be cracked.
The "WPA" series are a bit more secure than the "WEP".
But professionals, given time and the right equiptment, have also cracked
even the newest of the WPA series.
I suggest you read this short piece at Window XP Home.
http://www.microsoft.com/windowsxp/using/n...y/wireless.mspx