Ever since I bought my G5 1,8 GHz I had to fight with constant inaccessibility of PPPoE after 2 hours, rendering the complete SystemUIServer process stuck. It is documented in the relevant Technote by Apple (see link list below). It was a pain to use the machine, as other side effects occured like not being able to properly reboot or shut down the machine in those periods. Read the support thread for a full description of the problem. All this is fixed now with this Firmware update. I used the 10.4.3 version of this update, worked with no problems. It's only sad it took almost a year to get this fixed.


Support thread on mymac.ws (third post is mine):
http://www.mymac.ws/mac-internet-connect-hangs-on-disconnect-os-10-3-5-8242.html

Apple's Technote (third bullet point):
http://docs.info.apple.com/article.html?artnum=302212