Any of the following workarounds will resolve the issue. We expect a full fix to be forthcoming from Adobe.
Set the EPS Preview preference (QuarkXPress/Edit > Preferences > EPS) to Generate and then re-import the EPS file.
Resave the EPS in Photoshop CS5 with Preview set to TIFF (8-bits/pixel).
Resave the EPS in another format, such as PSD or TIFF.