Newbie with Process.Start problem

[mbailey]

I am new to VB.Net (Visual Studio 2005) and am encountering a problem calling an external exe file with two parameters. If I use the Run dialog box of the Windows Start menu and enter:
"C:\Program Files\TIES\Proposal.NET\HMSCCURV.exe" C:\1-28903T.TI C:\1-28903T.TO
everything works correctly. When the oProcess.Start() statement from my application shown below executes, I receive an error message stating "The parameter is incorrect":

' Previously established varaible values used in the code below:
calString = "C:\Program Files\TIES\Proposal.NET\HMSCCURV.EXE"
calFile = "C:\1-28903T.T"
 
' Set the process properties and start the external program.
Dim argString As String = calFile & "I " & calFile & "O"
Dim oProcess As New Process()
oProcess.StartInfo.FileName = calString
oProcess.StartInfo.Arguments = argString
oProcess.StartInfo.CreateNoWindow = True
oProcess.StartInfo.UseShellExecute = True
oProcess.Start()

When oProcess.Start() executes, oProcess.StartInfo.FileName = "C:\Program Files\TIES\Proposal.NET\HMSCCURV.EXE" and oProcess.StartInfo.Arguments = "C:\1-28903T.TI C:\1-28903T.TO". This exactly matches the manual entry in the Run dialog box, all of the file references exist, and there are no access restrictions to the files or directories.

Any suggestions?

Thanks,
Michael Bailey