Select Opacity Mask Items in Illustrator CS5

Does anybody know how to select both the opacity mask and the item being masked? I can select all page items, but when I try to set the position of a page item with an opacity mask applied to it, the mask stays right where it is…it doesn’t move at all.

yes, the mask and the masked artwork are linked together.

and it doesn’t seem to matter whether the .tif I’m using for the mask is embedded in the document or not.

Any ideas? I am well and truly stumped…

I should note:

Flatten Transparency will obviate the problem in CS3, but it does not appear to do so in CS5