Java HotSpot Virtual Machine

In Short:
Where can I find the source code to a particular JVM.DLL revision?

Details:
I'm working on a bug that seems to be related to code in JVM.DLL It looks like the JVM is trying to make use of a thread pointer to a virtual DOS machine (VDM) but because it is a NULL pointer, bad things happen. I think that the JVM is trying to make use of TEB->VDM because I disassembled the customer's crash dump in WinDbg and can see JVM code getting fs:[0x18] (the linear address of a thread execution block) and then the code adds 0xf18 to that. The value at this location is supposed to be a thread's VDM. A VDM is normally assumed to be a virtual DOS machine. Does the JVM normally store its own virtual machine pointer here? In any case, our diagnostics say that the following modules are installed:

J2SE Runtime Environment 5.0 Update 6 1.5.0.60
Java(TM) 6 Update 11 6.0.110
Java(TM) 6 Update 2 1.6.0.20
Java(TM) 6 Update 3 1.6.0.30
Java(TM) 6 Update 5 1.6.0.50

Which one of these is related to JVM.DLL and where can I find the source code for that version? I've downloaded jdk-1_5_0_03-fcs-src-b07-jrl-24_may_2005.jar through jdk-1_5_0_16-fcs-src-b02-jrl-28_may_2008 but the crash dump I'm working from can't be made to agree with the C++ source of any of them so I guess I haven't found the right source code yet Any suggestions on where I might find the source code that corresponds to the above list of possible revisions would be greatly appreciated.
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Richard Lewis Haggard