Fix problem with background configuration, evident with itcl 2.1.  Fix contibuted by Vince Darley.
Fix problem with background configuration, evident with itcl 2.1.  Fix
contibuted by Vince Darley.

svn path=/trunk/; revision=1958

FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot