Double download in nested lists

Hello everybody,

we have some custom lists with documents libraries in it. If you are in DisplayForm of an item, you can see the item plus a document library file (zip or whatever, some file format which will be downloaded onclick, no file format which can be opened onclick) which is connected to the ID of the item. If the item in the custom list is displayed normally (not in modal dialog) the download works correctly - if the item is shown up in modal dialog the download starts twice. Is this a known issue? 

Every help is appreciated.

Thank you.

Julien