[texhax] Difficulty getting bold greek letters

[dch]

Hi,

Apologies if anyone gets this twice, but I sent it earler from a webmail 
interface and it doesn't appear to have shown up on the list so here 
goes again:

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.