>I have a VFP8 app (which I can recompile for VFP9 if necessary) running on 4 Windows XP Pro SP2 PC's. All PC's are opening a DBF on the Windows 2003 server via a mapped drive Z: network share. To eliminate any DHCP lease timeout issues, all PC's (and server) are assigned static IP addresses (10.0.0.x) on the LAN. The 2 PC's connected right next to the Windows 2003 Server on the same switch never get an error. However, the 2 PC's that are in distant parts of the building connected via a VLAN get a mapped drive Z: does not exist error every so often. I tried changing the autodisconnect registry key on those PC's thinking it was the 15 minute autodisconnect "feature", but this had no effect. When I look in My Computer, drive Z: is there, with no red X on it. If I click on drive Z:, it takes perhaps 5 seconds to pull up the folders on the server, and all is well again. If there was a way to lengthen the timeout of my USE statement, to perhaps 10 seconds, I think this error would go away. Seems like VFP gives up a little too quickly.
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>I've tried running a ping -t 10.0.0.10 in a minimized DOS box to keep the TCP connection alive to the server, but this has no effect.
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>I've tried running a minimized VFP app that does a DIR Z:\ every 30 seconds to keep alive, but this has no effect.

Last time I had such an error, it was a W98 workstation getting disconnected from s W2k server (or vice versa). Turning the QoS service off in the disconnected machine seemed to fix the error (at least I haven't heard from them about this anymore).

Every new version of Windows brings up some new incompatibilities in the way files are open/closed/kept open across the network, if not all the machines are the same version of Windowses. Specially the Fox way of keeping files open doesn't seem to sit well - newer Windowses seem to like to break connections off to free the handles and seem to operate faster. Which is good for Word and whatnot - they don't keep files open like Fox does.