'Twas brillig, and the slithy toves did gyre and gimble in the wabe

For future reference: how to speed up network browsing under Windows XP and similar systems:

Delete or rename the registry key HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\RemoteComputer\NameSpace\{D6277990-4C6A-11CF-8D87-00AA0060F5BF} . No rebooting needed - this takes effect instantly.

This appears to control searching for scheduled tasks on other computers, which in some cases can take 30 seconds to fail (and in other cases just works - I have no idea why).

For more people saying "delete it", google the GUID.