I have a T43, WinXP Pro SP3, have updated to latest drivers using System Update.
After my system hibernates and I wake it up, I can't connect to web using either wifi or my pc-card 3g connection (verizon). My system shows that I am connected (Access Connections, under wifi, or Verizon's connect applet under 3g), but I cannot surf using browser, and I cannot send or receive email, which are the main things I need to do. Rebooting fixes the problem, and both wifi and 3g are working fine otherwise. I generally need web access, so in effect I can't use the hibernation feature, I have to reboot instead.
Context: my system is set to hibernate when battery reaches 3%. I only do this when traveling w/ out access to AC power, e.g. airplanes. I frequently run one battery down, until the system hibernates, I then swap batteries and resume. That's when I run into this problem = no wifi or 3g web access. If there's a better way to swap batteries, I'm all ears. I can't use standby, b/c you can't remove the depleted battery w/out killing the standby. I can't plug into AC, the whole point is this happens when I don't have access to AC power. FWIW, I had a Toshiba at one point that would let me swap batteries quickly using an internal backup battery, while the system was powered up. But I can't do that w/ the T43. I don't need hibernation for other purposes, I prefer standby generally.