Just as it quit, it began working again. Once Kinternet's icon appeared in the system tray, I was able to reconfigure it. Somehow, the setting had changed to manual detection of smpppd, after switching it to autodetection it works fine.
Rig 1: HAF 922, X2 4400+, Asus A8N32-SLI Deluxe , 4x1GB DDR400, 2x500GB, 1x80GB & 1x250GB + ESATCASE2 w/2x1TB HDs, LG CH10LS20 & GH22LS50, Samsung SH-S202N, Asus Xonar D2X,Creative 5.1, GTX460 SC, FusionHDTV7 Gold RT, Acer X233H, Arris TM520G, Cisco E3000, Scythe Kama, CM RS600 PS,HP 5510v,APC BX1000, XP x64, W7 & Kubuntu 9.10
Rig 2: Antec SX1040BII, A8N-SLI, 2x1GB DDR400, 8800GTS, 1x500GB & 1x1TB HDs, Liteon LH-20AIL and Pioneer DVR-111, Audigy 2 ZS, Creative T20 2.1, Antec 500SP, W7 x64 & XP MCE