File texlive-2007-beamerblocks.patch of Package texlive-texmf
diff -up texmf-dist/tex/latex/beamer/beamerbaseboxes.sty.beamerbox texmf-dist/tex/latex/beamer/beamerbaseboxes.sty
--- texmf-dist/tex/latex/beamer/beamerbaseboxes.sty.beamerbox 2006-01-13 00:52:02.000000000 +0100
+++ texmf-dist/tex/latex/beamer/beamerbaseboxes.sty 2008-08-27 12:21:51.000000000 +0200
@@ -113,7 +113,7 @@
\setbox\bmb@boxshadowball=\hbox{\pgfuseshading{bmb@shadowball}}%
\setbox\bmb@boxshadowballlarge=\hbox{\pgfuseshading{bmb@shadowballlarge}}%
\fi%
- \setbox\bmb@colorbox=\hbox{\color{lower.bg}}%
+ \setbox\bmb@colorbox=\hbox{{\pgfpicturetrue\pgfsetcolor{lower.bg}}}%
\setbox\bmb@box=\hbox\bgroup\begin{minipage}[b]{\bmb@width}%
\vskip2pt%
\usebeamercolor[fg]{\bmb@lower}%