Error with Ant build copying files, “Access is den

I have a weird bug that is popping up in my Ant build. The build works as such: build.xml calls a new buildTargets.xml file, and in that file most of the work is being done. buildTargets.xml creates a bunch of new files in gwt-out/htdocs/** and another directory staging/htdocs/**. Basically, files are being created in gwt-out/htdocs and then copied into staging/htdocs. The error is that only one file is not being copied, and I am getting a java.IO.FileNotFoundException (Access is denied) error. The weird part is that the file changes from build to build.

At first I thought it was an Eclipse problem so I built through the command line, and a new (a different file than eclipse) was not being put into staging/htdocs, which was yielded the same error. I've attached what Ant has said with the -debug flag. The error seems to pop up when the files are being tokenized in buildTargets.xml. After searching around it seems that the most common response was to fix my permissions-- however the file is being dynamically created, and when I go to check on that file all permissions are enabled (except "Special"), so I don't think that's the issue.

Other SO questions similar to mine all deal with building on a remote server and fixing my permissions to that server-- however this is all local to my computer, so I'm not sure that is the issue either. Could it be an error with the copying task in the Ant build?

Here's the error:

BUILD FAILED
C:\CSDK\build\buildTargets.xml:253: Failed to copy C:\Users\admin\worksp
ace\BuildPortal\out\gwt-out\htdocs\war\BuildPortalTest.iOS_Bu
ild_Portal\sc\modules\ISC_DataBinding.js to C:\Users\admin\workspace\BuildPortal
\out\staging\htdocs\war\BuildPortalTest.iOS_Build_Portal\sc\m
odules\ISC_DataBinding.js due to java.io.FileNotFoundException C:\Users\admin\wo
rkspace\BuildPortal\out\staging\htdocs\war\BuildPortalTest.iO
S_Build_Portal\sc\modules\ISC_DataBinding.js (Access is denied)
        at org.apache.tools.ant.taskdefs.Copy.doFileOperations(Copy.java:907)
        at org.apache.tools.ant.taskdefs.Copy.execute(Copy.java:563)
        at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:292)
        at sun.reflect.GeneratedMethodAccessor4.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
        at java.lang.reflect.Method.invoke(Unknown Source)
        at org.apache.tools.ant.dispatch.DispatchUtils.execute(DispatchUtils.jav
a:106)
        at org.apache.tools.ant.Task.perform(Task.java:348)
        at org.apache.tools.ant.Target.execute(Target.java:435)
        at org.apache.tools.ant.Target.performTasks(Target.java:456)
        at org.apache.tools.ant.Project.executeSortedTargets(Project.java:1393)
        at org.apache.tools.ant.Project.executeTarget(Project.java:1364)
        at org.apache.tools.ant.helper.DefaultExecutor.executeTargets(DefaultExe
cutor.java:41)
        at org.apache.tools.ant.Project.executeTargets(Project.java:1248)
        at org.apache.tools.ant.Main.runBuild(Main.java:851)
        at org.apache.tools.ant.Main.startAnt(Main.java:235)
        at org.apache.tools.ant.launch.Launcher.run(Launcher.java:280)
        at org.apache.tools.ant.launch.Launcher.main(Launcher.java:109)
Caused by: java.io.FileNotFoundException: C:\Users\admin\workspace\BuildPortal\o
ut\staging\htdocs\war\BuildPortalTest.iOS_Build_Portal\sc\mod
ules\ISC_DataBinding.js (Access is denied)
        at java.io.FileOutputStream.open(Native Method)
        at java.io.FileOutputStream.<init>(Unknown Source)
        at java.io.FileOutputStream.<init>(Unknown Source)

Thanks.

I ended up using the retry task, and that seemed to work based off of Isaac's description of what was possibly going wrong.