Unable to view frame variables in Remote Debugging

I have setup remote debugging on vagrant.  I am able to setup breakpoints and step through the code, but not able to view the frame variables.  When a breakpoint is hit the threads show up as Dummy-nn, where nn is some number.  I am unable to see any variables.  The error shown is

Traceback (most recent call last):
  File "/home/vagrant/.../pydev/pydevd_comm.py", line 871, in doIt
    result = pydevd_vars.evaluateExpression(self.thread_id, self.frame_id, self.expression, self.doExec)
  File "/home/vagrant/.../pydev/pydevd_vars.py", line 389, in evaluateExpression
    frame = findFrame(thread_id, frame_id)
  File "/home/vagrant/.../pydev/pydevd_vars.py", line 297, in findFrame
    raise VariableError("findFrame: must execute on same thread")
VariableError: findFrame: must execute on same thread

When I start the python process, and breakin initially, it shows the variables in the MainThread, but later when the breakpoints are hit, the variables are not shown.