If Uwe can give me a description how to produce this error. I never saw it (I don't use any math, though).
To reproduce: Load the LyX template that comes with beamer v2.10 and run pdflatex.
When enabling the use of amsmath all would be fine. But Angus fixed the problem, thanks.
And here the good news: This morning beamer v2.11 was released. It could be downloaded from
http://www.ctan.org/tex-archive/macros/latex/contrib/beamer
It fixes the incompatibility with xcolor v1.10 but requires now the packages pgf v0.61 and xcolor v1.10. It also fixes the problem with boldsymbol:
"Actually, the problem is just the missing checking of "use
amsmath" in Layout > Document > Packages. This is fixed in
version 2.11."
Therefore beamer provides a new LyX template.
Thanks for your help. regards Uwe
