It seems that FVWM does not back windows which are on some non-CurrentPage. If I run xwd -id $someWindowNotOnCurrentPage the image comes out as completely black. I would request that FVWM exposes a configuration option that would keep windows backed in memory such that programs like xwd produce a usuable result even when they aren't on the current page. Perhaps it would be nice to have this feature be both a global tri-state (off, on for current desk, on for all desks), as well as a per-window option toggleable via Style or Pick type actions.
Thanks in advance, -jesse
