I had this same problem on build 5270 and I was hoping this would work better on build 5308, but alas, I just can't get it to work.

Here is my basic network setup:

Cable modem connected to a Linksys RT31P2 router (wired) and then I have a Windows XP machine and then the Vista b5308 machine.

When XP is installed on the one with Vista now, I have no problem at all with network shares. Now with Vista installed, I don't even see the XP machine listed in my workgroup. At one point, I could see the files on the XP machine, but the next second, they were gone.

On the XP machine, I can see Vista machine in my workgroup, but I can't access it at all.

Is there a wizard I can go through to set this all up? Specific settings? Any suggestions would be appreciated.

As a side note, here are the specs of the machine running Vista:
DFI UltraInfinity motherboard with Athlon XP 3200+
1 GB DDR400 RAM
Geforce 6600 (regular, not GT) with 256MB
2x Seagate 200GB SATA drives in RAID 0 under onboard Silicon 3114 SATARaid (Vista had no problem using the XP Mass Storage driver for this and is where Vista is installed)
1x Maxtor 250GB PATA drive
I am using both the onboard sound and the onboard Ethernet
Kworld 110 ATSC Tuner Card (believe it or not, this was found and automatically installed)

Make sure that the IP addresses are in the same subnet. If you have any firewalls, configure them to allow the IP address range in ur network. Finally, there is a wizard to configure ur network. Go into network connections and in network tasks click Set up a home or small office network. Just follow the onscreen prompts. I don't know if it's the same in Vista, but XP lets you make a disk to use on other PCs to configure them. Keep in mind though that this does nothing to you firewall if you have one.

I'm not sure what I screwed up, but I gave up and just reinstalled Vista again. This time, instead of changing any settings or trying any wizards, I went straight to network. And what do ya know, there my XP machine was with all its shared folders.

Guess the moral to this story is that sometimes its best to actually trust default settings and let 'em do their job.

Hopefully, by the time Vista RTMs, they will have tweaked the wizards and settings more so that custom configurations can be more easily achieved. (That Network List feature that it has will be very useful for laptops that connect to multiple networks)

I had the same problem with XP and 2K. Turned out 2K networking wont work well with Simple File Sharing turned on in XP.