Will Not Work Without Rebooting

Every time I start thinking Vista is not so bad I make the mistake of trying to connect to another Vista computer. Although all sharing/permissions are properly set and it worked the last time it will not work when needed again without rebooting one or more computers. This is why mine and nearly every business on the face of the Earth has not adapted Vista: it is totally unsuitable for mission critical networks of any size. XP is far from perfect but it is orders of magnitude more stable for networking. Vista SP3 or whatever name Microsoft thinks they can peddle the same schlock under is a deader than dead issue already because it is nothing but Vista with a marginally different GUI and with the economy the way it is who gives a rat's behind about it anyway?