TC build hanging

Another hanging problem... sometimes an agent will hang while executing a build target. The output from the agent is:
Fatal error parsing XML: org.xml.sax.SAXParseException: Premature end of file.
Fatal error parsing XML: org.xml.sax.SAXParseException: Premature end of file.
Fatal error parsing XML: org.xml.sax.SAXParseException: Premature end of file.

over and over....

here's the thread dump:
Full thread dump Java HotSpot(TM) Client VM (1.5.0_11-b03 mixed mode):

"Thread-1" daemon prio=6 tid=0x0ac7ae70 nid=0xc88 runnable [0x0aecf000..0x0aecfd
6c]
at java.io.FileInputStream.readBytes(Native Method)
at java.io.FileInputStream.read(FileInputStream.java:194)
at java.io.BufferedInputStream.fill(BufferedInputStream.java:218)
at java.io.BufferedInputStream.read(BufferedInputStream.java:235)
- locked (a java.io.BufferedInputStream) at jetbrains.buildServer.agent.LauncherProcessOutputRedirector.readLine( LauncherProcessOutputRedirector.java:53) at jetbrains.buildServer.agent.LauncherProcessOutputRedirector.run(Launc herProcessOutputRedirector.java:36) "Thread-0" daemon prio=6 tid=0x00acfd70 nid=0xf00 runnable [0x0ae8f000..0x0ae8f9 ec] at java.io.FileInputStream.readBytes(Native Method) at java.io.FileInputStream.read(FileInputStream.java:194) at java.io.BufferedInputStream.read1(BufferedInputStream.java:254) at java.io.BufferedInputStream.read(BufferedInputStream.java:313) - locked <0x02ff3710> (a java.io.BufferedInputStream) at java.io.BufferedInputStream.fill(BufferedInputStream.java:218) at java.io.BufferedInputStream.read(BufferedInputStream.java:235) - locked <0x02ff3730>]]> (a java.io.BufferedInputStream)
at jetbrains.buildServer.agent.LauncherProcessOutputRedirector.readLine(
LauncherProcessOutputRedirector.java:53)
at jetbrains.buildServer.agent.LauncherProcessOutputRedirector.run(Launc
herProcessOutputRedirector.java:36)

"Low Memory Detector" daemon prio=6 tid=0x00a94e20 nid=0x9e4 runnable [0x0000000
0..0x00000000]

"CompilerThread0" daemon prio=10 tid=0x00a93aa8 nid=0x868 waiting on condition [
0x00000000..0x0abcf84c]

"Signal Dispatcher" daemon prio=10 tid=0x00a92e20 nid=0x430 waiting on condition


"Finalizer" daemon prio=8 tid=0x00a89cd0 nid=0x3e0 in Object.wait() [0x0ab4f000.
.0x0ab4fc6c]
at java.lang.Object.wait(Native Method)
- waiting on (a java.lang.ref.ReferenceQueue$Lock) at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:116) - locked <0x02fd5380> (a java.lang.ref.ReferenceQueue$Lock) at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:132) at java.lang.ref.Finalizer$FinalizerThread.run(Finalizer.java:159) "Reference Handler" daemon prio=10 tid=0x00a88858 nid=0xab8 in Object.wait() [0x 0ab0f000..0x0ab0fcec] at java.lang.Object.wait(Native Method) - waiting on <0x02fd51f8> (a java.lang.ref.Reference$Lock) at java.lang.Object.wait(Object.java:474) at java.lang.ref.Reference$ReferenceHandler.run(Reference.java:116) - locked <0x02fd51f8>]]> (a java.lang.ref.Reference$Lock)

"main" prio=6 tid=0x00036df0 nid=0x8e8 runnable
at java.lang.ProcessImpl.waitFor(Native Method)
at jetbrains.buildServer.agent.LauncherBase.launch(LauncherBase.java:160
)
at jetbrains.buildServer.agent.LauncherBase.Start(LauncherBase.java:349)

at jetbrains.buildServer.agent.Launcher.main(Launcher.java:53)

"VM Thread" prio=10 tid=0x00a85d80 nid=0xc20 runnable

"VM Periodic Task Thread" prio=10 tid=0x00a961b0 nid=0x7c4 waiting on condition