Have Optus changed their Edge / GPRS / APN settings?

Until the last few days I could use GPRS for Safari / Mail / Weather etc on my 1st gen iPhone with Optus using the following settings (Settings > Network > Edge):

APN = Internet
Username = guest
Password = guest

But nothing for a few days now. Has Optus changed the settings required?

BTW, searched and couldn't find an answer on MTAU either here or here or here.

Username and password should be blank always have been for me.

+1, blank for both entries

It's case sensitive:

"internet"

Thanks gaehl, TommyMac and lenier. Strange that your 1st Gen Optus internet is working and mine is not.

These settings worked until a couple of days ago. I've tried using blank for username/pw without luck. I've tried capitalising and not capitalising.

I've now sent an email to Optus support. I'll update if / when they reply.