Conditional formatting over a picture

I'm using Access 2002, and I'm imprinting a watermark on my report by
setting the Picture property of the report to my image. My report contains
several subreports, and the picture image underlies these subreports.
Everything looks fine except for one subreport, which uses conditional
formatting in its fields. Under this subreport, the picture is 'blocked' by
white boxes where the subreport fields overlie the picture. None of the
other subreports have this effect, and since none of the other subreports
are using conditional formatting, I am assuming that is the source of the
effect.

I have looked at the subreport fields, and all have their Back Style
property set to Transparent. In the Conditional Formatting dialog, there is
no option for me to specify a transparent background; I can only select a
background color. So the conditional formatting seems to be 'overriding' the
field Back Style property. Is there a way to make the fields transparent
when conditional formatting is used?

Thanks for any information,

Carl Rapson