MultiSelect Field Fails to Populate Current Values in Behalf of Organization Profiles

Multiselect Fields are not populating in profiles with the saved values - and worse, the saved values are removed from the select list.

This is observed on client's 4.5.6 site as well as the current demo site. This is specifically affecting an organizational profile included on a membership renewal as a "on behalf of" profile.

It can be recreated by:
1) create an organizational custom field of type=multiselect
2 )add the field to a profile that can be used for the on-behalf-of-organization profile
3) create a contribution page for membership and select the "on behalf of organization" option and choose the profile referenced above
4) for an organization, make some entry in the multi-select field.
5) make/verify there is a permissioned relationship to an individual
6) create a checksum link to the contribution page from that individual's record.

Following the checksum, the multi-select field will only show the options NOT selected for that contact. The already selected & saved options are hidden.
Everything else on the contribution page works as expected ... but ALL multi-select fields fail to display the saved selections.

Note, this behavior is NOT seen if a multi-select field is added to an Individual record and placed in a contribution page.

As long it lasts, here's a checksum link to the demo site ...
http://d46.demo.civicrm.org/civicrm/contribute/transact?reset=1&id=5&cs=714b9036c5d1f0b7455547ff2428c3f6_1429292600_168&cid=208