perhaps, you could access the listbox in the browseEntry ($browseEntry) with the following (untested):

my $lb = $browseEntry->Subwidget('slistbox');
[download]

and change the font for $lb. I think you can do something with all such composite subwidgets that are "Advertise"d in the Modules-Code

Best regards,
perl -le "s==*F=e=>y~\*martinF~stronat~=>s~[^\w]~~g=>chop,print"