TID 7002814 says:
Any multi line registry data cannot contain empty string in its value field.

Fair enough... but an application that I am distributing does indeed put in a multi line registry data that IS empty. I think that this empty entry may be appended to in the future.

If I add the empty multi in the Registry Edit action, I get a registry edit error and the bundle fails.

A normal registry export (from the registry, not ZCM) has this blank multi and if I import directly to the registry (Win7) from the reg file it imports fine. This seems to be a limitation from ZCM?