Pro/Desktop Express (Service Pack 1)

At there is a download for Pro Desktop Express
(Service Pack 1) which apparently resolves a long standing problem
with PDEx v8.0
Actually, I'm new here so I'm not familiar with the problem that has
caused "so much grief" according to the comment on the www.prodesktop
home page - could someone give me a quick resume of what it was
Can someone confirm that this works. Anyone installed this
successfully yet - does it do the trick?
I downloaded the Pro/D Express program from a couple of
weeks ago now - can I assume that this is NOT the 'fixed' version - is
there an easy way to check - is the only remedy to download the whole
33Mb file - I take it there's no 'patch' available from ptc.
If I install the new version (SP1) will I need a new activation key?
I'm enjoying my evaluation of Pro/D X but being new to 3D modelling I
must say I don't find it particularly intuitive. However, the
tutorials referred to in this group and elsewhere have been a great
help.
Thanks in advance.