NB 4.1, Profiler M7, JDK 1.5.0_04, Freeform project with targets 'profile' 
and 'profile-single' using the 'nbprofile' task.

Preface:
The profiler is only accepting the build script in NB's project directory, but 
I used to store it elsewhere, which is no problem to integrate in a NB's 
freeform 'project.xml'.

'project.xml':

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://www.netbeans.org/ns/project/1">
    <type>org.netbeans.modules.ant.freeform</type>
    <configuration>
        <data xmlns="http://www.netbeans.org/ns/profiler/1" profile-file-
target="profile-single" profile-target="profile" version="0.4"/>
        <general-data xmlns="http://www.netbeans.org/ns/freeform-project/1">
            <name>MyProject</name>
            <properties>
                <!-- HERE is the entry point for all project initialization
                     (including the build script's location)! -->
                <property-file>nbproject/project.properties</property-file>
...


So, it would be very helpful to define the (name AND path) of the build script 
in a profiler property that's read within the project.xml's 'profiler' node 
(currently 'data' - which I can't find in the corresponding xml-schema?!) or 
the 'general-data' node.

I worked around the problem with a second build script importing the original 
one, so the error 'Can't find build.xml' disappeared and 'Profile Project' 
works.

But using 'Profile File' generates the following error (before the build.xml 
target 'profile-single' is even called):

java.lang.IllegalArgumentException: Tried to pass null folder arg
  at org.openide.filesystems.FileUtil.isParentOf(FileUtil.java:837)
  at org.openide.filesystems.FileUtil.getRelativePath(FileUtil.java:625)
  at 
org.netbeans.modules.profiler.freeform.FreeFormProjectTypeProfiler.configureProp
ertiesForProfiling(FreeFormProjectTypeProfiler.java:134)
  at org.netbeans.modules.profiler.actions.AntActions.doProfileProject
(AntActions.java:312)
  at org.netbeans.modules.profiler.actions.AntActions.access$000
(AntActions.java:40)
  at org.netbeans.modules.profiler.actions.AntActions$1.perform
(AntActions.java:67)
  at org.netbeans.modules.profiler.actions.FileSensitiveAction.actionPerformed
(FileSensitiveAction.java:47)
  at 
org.netbeans.modules.profiler.actions.ProjectSensitiveAction.actionPerformed
(ProjectSensitiveAction.java:86)
  at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1849)
  at javax.swing.AbstractButton$Handler.actionPerformed
(AbstractButton.java:2169)
  at javax.swing.DefaultButtonModel.fireActionPerformed
(DefaultButtonModel.java:420)
  at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:258)
  at javax.swing.AbstractButton.doClick(AbstractButton.java:302)
  at javax.swing.plaf.basic.BasicMenuItemUI.doClick(BasicMenuItemUI.java:1000)
  at javax.swing.plaf.basic.BasicMenuItemUI$Handler.mouseReleased
(BasicMenuItemUI.java:1041)
  at java.awt.Component.processMouseEvent(Component.java:5488)
  at javax.swing.JComponent.processMouseEvent(JComponent.java:3126)
  at java.awt.Component.processEvent(Component.java:5253)
  at java.awt.Container.processEvent(Container.java:1966)
  at java.awt.Component.dispatchEventImpl(Component.java:3955)
  at java.awt.Container.dispatchEventImpl(Container.java:2024)
  at java.awt.Component.dispatchEvent(Component.java:3803)
  at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4212)
  at java.awt.LightweightDispatcher.processMouseEvent(Container.java:3892)
  at java.awt.LightweightDispatcher.dispatchEvent(Container.java:3822)
  at java.awt.Container.dispatchEventImpl(Container.java:2010)
  at java.awt.Window.dispatchEventImpl(Window.java:1774)
  at java.awt.Component.dispatchEvent(Component.java:3803)
  at java.awt.EventQueue.dispatchEvent(EventQueue.java:463)
[catch] at java.awt.EventDispatchThread.pumpOneEventForHierarchy
(EventDispatchThread.java:242)
  at java.awt.EventDispatchThread.pumpEventsForHierarchy
(EventDispatchThread.java:163)
  at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:157)
  at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:149)
  at java.awt.EventDispatchThread.run(EventDispatchThread.java:110)