add-hours validation error messes up "repeats" panel

[ccg]

go to /officehours/event/create/ and add some office hours. check "repeats" and select an end date and some days of the week to repeat. put in a validation error, e.g., make the end time earlier than the start time. click Save. the form returns with the validation error. the "Repeats" panel is still filled out, but it's greyed out. UNcheck "repeats" to unhide the Repeats panel. in other words, the bit is flipped. the panel is hidden when it's supposed to be visible.