(I'm putting this in a new thread so it'll be easier to find for the next person who trips over this.)
The thinkpad w520 has a dual-mode video system called "optimus" - both an intel graphics adapter and an nvidia adapter are active at the same time. (And in some cases one can drive the laptop display while another can drive an external display.)
This seems to cause solidworks grief. One workaround is to start it, and it hangs at the splash screen. Then start a 2nd instance, which will suceed, kill the 1st one, and away you go.
A better solution (for me) is to go into the w520 bios (F1 at startup) and change the bios config to be "discrete only" - so use the 1000M for ALL video, turn the intel adapter off.
This allows solidworks to start and work without hanging at the splash screen. (But may or may not cause grief in dual-monitor mode - I have no idea.)