Caroline, Andrew,
The "set curriculum_bar_p" statement in site-master.tcl has been cached on openacs-5-1-0-final, openacs-5-1-compat and HEAD.
Jeff wrote me (in private) and pointed out that I shouldn't use util_memoize in the page. I agree with that. He suggested a proc like so:
site_nodes::package_mounted_p package_name site_node
...which would return the memoized result for the curriculum package and other packages as well.
He said he would also add a flush in the mount to flush the memoized ones for a given package_name.
I haven't gotten around to do this yet, but it is my intention to follow his advice sooner or later.