Dynamic Build does *nothing*

[jmm]

I am having problrms trying to run a dynamic build from a Run Script. I couldn't find any sample code that did what I want, so guessed how to do it; I am most likely doing something wrong. The relevant chunk of the Run Script (VBScript) looks like:

Dim objBld, objApp, objMacro
Set objBld = CreateObject("VisBuildSvr.Builder")
Set objApp = CreateObject("VisBuildSvr.Application")
objBld.Initialize objApp
objApp.Project.Load "%PROJDIR%\BuildVB6.bld"
Set objMacro = objApp.Project.Macros.Add("PROJFILE", ProjFile)
Set objMacro = objApp.Project.Macros.Add("BLDVERSION", "1.2.3")
Rslt = objBld.SyncBuild
if Rslt <> 0 then
msgbox "Error - Build of " & ProjFile & " returned " & Rslt & "!", vbOKOnly, "Parser.bld"
end if


The called VBP project file ("%PROJDIR%\BuildVB6.bld") contains:

<?xml version='1.0'?>
<project version='5'>
<step action='Make VB6' type='0'>
<Attr type='11'>-1</Attr>
<BinCompat type='11'>-1</BinCompat>
<Filename>%PROJFILE%</Filename>
<IncrReason type='11'>-1</IncrReason>
<Version>%BLDVERSION%</Version>
<VersionSel type='3'>2</VersionSel>
<ignorefail type='11'>-1</ignorefail>
<indent type='3'>2</indent>
<name>VB6 build</name>
</step>
</project>


The facts as known:
1) BuildVB6.bld is being read: if I hide it I get a "can't find it" error.
2) objBld.SyncBuild always returns 0 and produces no log output.
3) objBld.SyncBuild always runs *very* quickly.

Can someone suggest what is wrong?

Thanks in advance - Michael