Network list of computers inaccurate

[wigglytoes]

I'm working on a Win7 Ultimate x64 - (Up to date with latest updates)
I have a small 'work' network with 9 computers on it.
several Win7, one Win XP x64, one Win Xp, several Linux (5.10 and 6.5)
The Linux machines communicate with Windows machines via Samba.
I turn these computers turn on and off, as I use them. IE the computers that are running, on the network, vary from time to time.

When I open a Windows Explorer and click on Networks, the only time that I will see an accurate representation of the computers that are actually running is right after boot.
Sometimes I can see an icon for a computer that I know is turned off.
Sometimes there is no icon for a computer that I know is running.
This only happens with the Win7 machines. XP and XP x64 work fine.

I have played with the Advanced Sharing setting continuously, but with no luck.
Network Discovery is always turned on. (as is file and print sharing, and 128-bit encryption)
Right now Password Protected Sharing is off, and I'm using user accounts and passwords to connect to other computers.
There doesn't appear to be rhythm or reason why on computer's icon will appear while another will not. The OS of the other computers doesn't matter. It appears to be real hit and miss.
I'm lost as what to try next.

There is a related oddity.
The network keeps changing names, and even type of network.
I generally run this computer for days/weeks at a time.
I looked today, and suddenly it was a Public network, (All Windows computer are set to 'work network'.)

I'd appreciate any help, or direction of investigation.

Wiggly

 

[2xg]

Welcome to Seven Forums,

I'd look first on physical cabling of your network, is this professionally done? What type of network cables are you using? Also, interference might cause this issue. Check on what type of network Switch(es) you're using, are they old? Gig switches might be viable.