[Guy Harris <guy@xxxxxxxxxx>]

> When I start ethereal I get the following errors:

UCD SNMP 4.2 has a bug in it, I think, causing those messages; 4.2.1
doesn't appear to have this problem.

> The GUI starts but then when I try to capture traffic I get the following:
> 
> Unable to parse filtering string (parse error)

What was the capture filter expression you typed into the "Filter:" text
box in the "Capture Preferences" dialog box?  It was probably not a
valid capture filter expression; note that the syntax for capture
filters is *not* the same as the syntax for display filters, but is,
instead, the same as the syntax for filters in tcpdump (because Ethereal
and tcpdump use the same library for doing packet capture).