Redmine

Hi All
I am running into a problem, I have created a multi select custom field, its a checkbox with a couple values (one, two, three, four). I can select these items when manually creating an issue in the web interface. I can export the issue as csv (and open in excel) and it shows the multiple selections separated by a comma in the cell, but when i try to import that issue from the csv the values are blank.. i lose them.

Is there a specific format? i tried wrapping each item with quotes (double and single) or all the items.. but get nothing.