>>Thanks guys, but I'm stuck with this for now. It turns out that if you get the image into the field on a machine that doesn't display this behaviour, it shows OK on a machine that does.
>>
>>Luke
>
>The problem with general fields, is that the content is linked to an application to handle the content. If that application is missing or faulty, you have the problem you describe. I always call a general field a WROM field; WRite Only Memory. :-)

Somewhere in Googleland, I believe I that I have seen a writeup on how to overcome this limitation, but I've never tried it.