My puppy install can't connect to my wireless network using the setup wizard (it connects to the wireless, but can't get an IP address from the DHCP on the router).

However, after a bit of digging around I found the following put into a script to work for my network...

It works great from a single click after the laptop has booted. However, I can't get it to run at startup. I've tried placing it in root's "Startup" directory. No joy. I've also tried adding a link to it in "/etc/rc.d/rc.local", even placing the script in "/etc/rc.d/" and calling it "rc.netstart" and still nothing happens until I run the script manually.

Any ideas?

The last two notebooks I had were very special concerning "when" to start up wireless.
With the first one I had to wait 30 sek. after the boot sequence was completed, otherwise it refused to work.
With this one I have to start it up as soon as possible after boot. Doing it later manually won't work (needed a few days to find this out).
So, give it a try - measure how long you wait since boot has completed (excl. yourself logging in) and insert a "sleep" command at the beginning of your script for the time you usually need to start wireless manually.

What shall I say...

Thank you, that worked!

You're welcome
Weird, isn't it?!