Cleared for an approach, then given a different altitude assignment

Peter R. writes:
KP (nospam@please) wrote:

What class of airspace were you in?

Class E airspace making a GPS approach while VFR into a class C airport
(we were still several miles outside the class C ring).

If Class B or C the answer is probably "Yes, he should have cancelled
approach clearance to be 'book correct." But maybe he decided ensuring
separation was a higher priority task. Or has the view that if he told you
to maintain 3000 it should be obvious to you you're no longer authorized
descend on the approach (not saying it is; saying he thinks it should be
-/ ) .

The other issue that prompted my confusion was the controller change.
One controller cleared me, the next issued an altitude restriction. Was
the second's altitude restriction due in part to the fact that he was
not familiar with the GPS approach?

http://www.myairplane.com/databases/.../00411RY15.PDF

On the chart above, we were still outside of PAGER, approaching from the
east, when this occurred.

The approach required at least another 5 miles west at 3,000, then 12
more southwest-bound at 3,000 before descending - with strong headwinds
that day I had at least another thirteen minutes at 3,000 without the
altitude restriction. The other VFR aircraft was 500 feet below us
crossing our path at a 90 degree right to left direction and was well
south of us a minute or so after the restriction.

Am I missing something?

You were assigned an altitude that you were going to
maintain without the assignment?

It would seem that letting the assignment pass without
comment and simply waiting for the controller to remove
the altitude restriction, probably with the words "cleared
for the approach", would have worked. If the restriction
weren't removed before needing to start the descent, a
verification of the approached clearance would then be
in order.