I switched to Matlab 2012b (from 2011a), but fail to find out how to start the profiler gui in the new matlab gui.
AFAIK, this should still work:
profile viewer
while we're at it, these tweaks should still work, too:
profile -memory on
setpref('profiler', 'showJitLines', true);
I don't have the opportunity to check, but you mean to say that R2012 doesn't have the little button on the top anymore?
The GUI option is still there, in the editor tab:
You will be able to specify input parameters once the function has crashed ;)