[plt-scheme] DrScheme buglet?

In v371 of DrScheme, it appears that teachpacks don't "stick."

When you first open a DrScheme window, even though it says that a
teachpack is loaded, it's unavailable until you hit Run.

That's not a big problem, but the teachpacks disappear if there's an
error during a Run. In other words, if students are developing a
function, hit run, and have an error, if they drop down to the
interactions window to experiment, the functions provided by the
teachpack are no longer available.

The workaround is to comment out offending code in the definitions
window, but this is kind of a pain.

Todd