microstation fit view issue

hi all,

microstation noob here!

we have a dgn file that (all of a sudden) when is opened, does not display correctly when fit view - all is used, but displays correctly when fit view - reference is used.  when fit view - all is used, the drawing does not fill the layout screen, but fit view - reference fills it out as expected.

this hasn't always been the case.

we have tried looking for rogue objects but have not found any. 

microstation version is v8

i am sure it is something simple, but i have only just started as a support officer and haven't had microstation training as yet.

any help would be greatly appreciated.  if you require more info, i can get it for you.