DME Format Tree is Saving Incorrectly

I am trying to create a new DME format tree, transaction code DMEE. I can populate the source fields but when saving or activating the format, entries on all fileds will be moved to the center of the fields. As a result these entries are not being recognised. For example if the file is be populated by a constant value like "SARS", I can enter that constant value as the source field. But if I activate the format this constant value changes to " SARS". Some spaces will be entered on the left.

Does anyone know what could be causing this?