First of all make sure you have set up your Network shares password setting correctly:
The “flaw” you mention is really a Windows flaw in my opinion; the master browser thing is it’s problem. With all those PCs going on and off, no wonder the master browser situation get bunged. You likely have a PC you consider your “main” one. So, turn all off except that one, and reboot the router. After a while you can check that the main PC is the master brower (using the tool mentioned above). Now, don’t turn this PC off – ever, and if you do, then you need to reboot the router again as described.
If you have a fairly new router, it might have a setting to make the router the master browser. I do with mine. If the router can be the permanent MB (because one hardly ever turns off a router), your problems are basically solved in that dept.
