Try putting -p1 instead of -p0 in your spec file.
%patch0 -p1 -b -z (do you know how desperate I must have been to even try that? I found it in the How-To.)
There appears to be a problem in the %files section too.
Processing files: lxdm-0.2.0-1pclos2010
error: File not found by glob: /home/joe/src/tmp/lxdm-0.2.0-1pclos2010-buildroot/usr/bin/*
Still looking at it.
Still haven't found out the deal with Thunar context menus. Getting familiar with the command line again.