Can't share files in my network, vista + xp machines!

I have my dekstop machine running windows vista ultimate 32bit,
a lenovo T61P running windows xp pro sp3, p4 desktop running windows xp pro sp2.
My main machine that's running vista ultimate can see and access the 2 other machines fine, copy, delete,
move files to them with no problem. But, my other 2 machines can't access my main machine for some reason.
I can browse my network places in my t61p wirelessly and see a bunch of files in my main desktop
but can't access them, the same goes with my other desktop machine that can see shared folders
in my main machine but can't access them. All of them are in the same workgroup, windows firewall

is disabled in all of them. I ran both xp pro machines through "network setup wizard" and
enabled file sharing. In my main machine, network discovery, file sharing, public folder sharing,
media sharing are all enabled, while password protected sharing is disabled. All of them connect
through a linksys WAG200G ADSL router. I keep getting a message. XX is not accesable, you might
not have perm...ect


The thing is, file sharing was working fine before I bought my laptop couple of
weeks ago. I could browse/delete/move files shared in my vista ultimte machine & the p4 xp pro machine
fine, but now I can't do that for some odd reason. I trippled checked my settings and they seemed fine, windows firewall is turned off, all machines in the same workgroup, I can access the other machines from my vista ultimate machine, but not the other way around..
P4 machine using ethernet, while t61p using wireless, my main vista ultimate machine is using ethernet.

 

Install the Link Layer Topology Discovery (LLTD) Responder (KB922120) on the XP machine.

And make sure all pc are on the same workgroup, def are different between XP and Vista.

http://www.microsoft.com/downloads/details.aspx?familyid=4F01A31D-EE46-481E-BA11-37F485FA34EA&displaylang=en

 

As blue68f100 said. I had this same issuue and the Link Layer Topology Discovery (LLTD) was the fix. Download here at Microsoft: http://www.microsoft.com/downloads/details.aspx?FamilyId=4F01A31D-EE46-481E-BA11-37F485FA34EA&displaylang=en

Also more info here in Wikipedia: http://en.wikipedia.org/wiki/Link_Layer_Topology_Discovery

 

Thanks alot guys for the helpful posts. I disasembled my p4 disktop few hours ago, and woun't put it together till tomorrow so I'll install that fix tomorrow and hopefully it'll solve the problem with the xp machine. I installed windows vista ultimate X86 on my t61p today, enabled file sharing, network discovery, disabled widows firewall, it's in the same workgroup as my vista desktop. But, I still can't browse my desktop's files wirelessly. What do you guys recommend me to do to troubleshoot this issue? I've googled for the answer, but to no avail. I've checked services under both machines and made sure all the networking services are started and all.

 

can u ping both machines, from one to another?

cheers ...

 

Yup, I can ping both, 1-2ms and no lost packets.