32 bit or 64 bit Natty

I have earlier tried both 64bit and 32bit distributions of Ubuntu for running IBM workstation SW, and have found that with a 32bit PAE kernel I get the best results. This is on newer thinkpads that have the appropriate processor flags for running (if you need it) 64bit VMWare/Virtualbox guests. Internal IBM print and java are examples that have been giving me problems on 64bit Ubuntu.