[OS X TeX] bold fonts in math mode

[Gerard Walschap]

	For some reason, I can't get lower-case greek letter to appear in bold. For example $\mathbf{\gamma}$ produces the same output as $\gamma$. There is no such problem with upper-case: thus, $\mathbf{\Gamma}$ does produce the bold version of $\Gamma$. The same thing happens replacing \mathbf by \bf. I'm using texlive 2008 and TeXShop 2.26. Any ideas?

	Thanks,

	-gerard