Mathlink and Parallelization

Question

Possible Duplicate:
How to run mathlink external commands in parallel?

Abstract

I have a binary file compiled to work with MathLink. I can install the file and run the component functions from within Mathematica without any problems. But, when I try to use Mathematica's inbuilt parallelization with calls to my binary, I get an error that says

LinkObject::linkn: Argument LinkObject[/path/to/binary/file.binary,14,8] in
 LinkWrite[LinkObject[/path/to/binary/file.binary,14,8],CallPacket[1,{1,2066455,5.,200000}]]
 has an invalid LinkObject number; the link may be closed.

I understand this to mean that MathLink cannot set up links to my binary for some reason? How does one get this to work?

System Details

I am on a system with 8 cores running x86_64-redhat-linux-gnu.

Mathematica Code that Produces the Error

Assume SwitchTimes is a function defined inside my binary. It takes a number of inputs, but I want to loop over values for one particular input.

f[x_] := Module[{A, ma}, 
   A = SwitchTimes[x, RandomInteger[10000000], 5.0, 200000];
   ma = Mean[A];
   ma
   ];

B = ParallelMap[f, Table[i, {i, 1, 100, 2}]];

Code that runs fine

f[x_] := Module[{A, ma}, 
   A = SwitchTimes[x, RandomInteger[10000000], 5.0, 200000];
   ma = Mean[A];
   ma
   ];

B = Map[f, Table[i, {i, 1, 100, 2}]];