Discovery failing

[James]

I see this is a constant issue with SCOM 2007 R2, but i dont see any reliable
answer, i have checked that SQL is running sqlbroker and then double check
that it was true.

It can sit on discovery for weeks (i exited the RDP and forgot it was
discovering and logged back in a week later) to no avail, i have tried a
manual install of the client agent, to have it join days later, but with no
monitoring options enabled. either im missing something really fundamental
here or its just not working for me.