[blabno]

Now this sounds like that request does not include conversation Id.
See if you can add <f:param/> with conversation Id. I also guess that <rich:paint2D/> does the second request as GET, am I right?

[poschd]

Yes, that's absolutely right. I didn't think about that, but <rich:paint2D/> drops the page's request parameter(s), so the request (which is indeed a GET request) does not include the conversation id.

Unfortunately, adding an <f:param/> doesn't work. Any alternatives? :-/

[amazur]

You can pass conversation object by data = "#{prescriptionAction}"
in
<rich:paint2D id = "painter" width = "400" height = "620"
            data = "#{prescriptionAction}" format = "png" paint = "#{paintBean.paint}"/>

and retrieve it from obj parameter on  paint(Graphics2D g2, Object obj) method