In macro mode, I just can't get the camera to focus in the display. I've tried extending to infinity, and then physically moving the camera in and out...then brought the lense to the opposite extreme, alternately moving the camera and focusing. It just won't focus. If I even bother to attempt a shot, it's just a blur.
The flash shouldn't enter into this, but I usually have it off. For the 10g countertop tank, I can handhold while bracing against the counter. That wouldn't come into play though, before the photo is even taken. Again, I think that I should be able to at least get a clear image on the display, even handheld.