Sage 5.0 plot issue

edit

Okay, so I've rebooted my Mac in 64 bit mode and am running Sage 5.0. When I do a plot3d and specify an opacity, I get the following error:

------------------------------------------------------------------------
Unhandled SIGILL: An illegal instruction occurred in Sage.
This probably occurred because a *compiled* component of Sage has a bug
in it and is not properly wrapped with sig_on(), sig_off(). You might
want to run Sage under gdb with 'sage -gdb' to debug this.
Sage will now terminate.
------------------------------------------------------------------------

I also get this on one simple interact that runs in the single cell server at sagemath.org/eval.html, which I assume is running Sage 5.0. Other interacts seem to run okay for me. The interact is:

var('x')
@interact
def test(a=slider(0,10,0.1,2),b=slider(-6,6,.1,0),c=slider(-3,3,1,1),d=slider(-4,4,1,0)):
   print 'Plot y = '+str(c)+'sin('+str(a)+'x + '+str(b)+') + '+str(d)
   p1=plot(c*sin(a*x+b)+d,(x,-6,6))
   show(p1)

I'm guessing that I don't have something set up right for Sage 5.0 to run correctly. Any ideas?