Descriptions/enumerations with a background

["Duncan Hothersall" <dh@capdm.com>]

Hello all,

I have been trying to set up an enumeration to have a background screen.
Having completely failed, I ended up putting a \startbackground ...
\stopbackground pair inside the \startsubactivity ... \stopsubactivity, but
this does strange things with page breaks, presumbly because it is
interfering with the glue between the enumeration title and the body of it.

Can anyone help me with a \defineenumeration or \setupenumeration parameter
that will make the background go grey? Here's what I have up top:

\defineenumeration[activity]
	[text=Activity,
	before={\blank[2*big]},
	after={\blank[2*big]}]

\setupenumerations[activity]
	[headstyle=\ss\tfa]

\setupbackground
	[background=screen,
	corner=round,
	offset=6pt]

Here's what I currently do, which doesn't work well:

\startsubactivity
\startbackground
This text sometimes jumps over a page break even when there is lots of space
on the page.

It can have more than one paragraph in it.
\stopbackground
\stopsubactivity

And here's what I'd like to do:

\startsubactivity
This text behaves well and has a grey box behind it.

It can have more than one paragraph in it too.
\stopsubactivity

Any pointers as to what to put at the top to make the bottom happen would be
gratefully received.

Thanks,

Duncan