CreateFile error trying to open pipe - c++

Question

I am trying to create a demonstration client/server application using named pipes on two Windows 7 machines, but cannot get this to work. The two machines, let's call them server and laptop, are both connected to an ethernet switch which is in turn connected to a cable modem. Both machines can see the internet, and both machines show up in the Windows network map. So I think they are correctly networked.
I am writing in Visual C++ and am basically copying the sample code on MSDN for a named pipe server and client. On my server, I call CreateNamedPipe() using the pipe name:
\\.\pipe\MyServerName
On the client, I call CreateFile with the pipe name of:
\\<machine>\pipe\MyServerName
where "machine" is configurable. If I run the server and client on the same machine, and for machine use either "." or "POWEREDGE" (the name of my server machine according to Windows), the two programs communicate fine.
Now I go to my laptop and run the client software. I use "POWEREDGE" as the machine name. CreateFile fails with GetLastError=1 ("Incorrect Function" apparently).
Any ideas about what could be going wrong here?
In response to requests, here is the actual code:
// CLIENT SIDE
// note: value of gLKServer is "POWEREDGE"
char PipeName[256]="";
wsprintf(PipeName,"\\\\%s\\pipe\\LKServer", gLKServerName);
while (TRUE) {
hPipe = CreateFile(
PipeName, // pipe name
GENERIC_READ | // read and write access
GENERIC_WRITE,
0, // no sharing
NULL, // default security attributes
OPEN_EXISTING, // opens existing pipe
0, // default attributes
NULL); // no template file
if (hPipe != INVALID_HANDLE_VALUE) {
break;
}
// Exit if an error other than ERROR_PIPE_BUSY occurs.
if (err=GetLastError() != ERROR_PIPE_BUSY)
{
printf("CreateFile error %lu\n", err);
}
...
// SERVER SIDE
char PipeName[256]="\\\\.\\pipe\\LKServer";
hPipe = CreateNamedPipe(
PipeName, // pipe name
PIPE_ACCESS_DUPLEX, // read/write access
PIPE_TYPE_MESSAGE | // message type pipe
PIPE_READMODE_MESSAGE | // message-read mode
PIPE_WAIT, // blocking mode
PIPE_UNLIMITED_INSTANCES, // max. instances
BUFSIZE, // output buffer size
BUFSIZE, // input buffer size
0, // client time-out
NULL); // default security attribute