[texhax] cannott get bold \mu

[David Carter-Hitchin]

Hi, 

Subject line says it all really.  Tried 

${\bf \mu}$
$\textbf{\mu}$
$\tmmathbf{\mu}$
$\mathbf{\mu}$ 

So far I've view the output with xdvi and xpdf.  I'm using pdfeTeX Version 
3.141592-1.21a-2.2 (Web2C 7.5.4) on a Linux box. 

Anyone any ideas?
Thanks,David.