Possible memory leak in ENMFP Codegen

I'm using ENMFP 3.15 (C++) under Ubuntu (64bit). I have a class generating fingerprints in a separate thread for an entire song. Whenever I create a Codegen object:

Codegen codegen(sampleData, size, 0);

and it runs out of scope (or creating a pointer and immediately delete it afterwards), about 20-30 mb of memory is never returned to the system. I've run this test about 20 times with the same result. The moment I remove the single statement that creates the Codegen object, the memory loss doesn't occur.

I haven't run Valgrind on it, but the memory is lost - it can't be reused by the program afterwards. Since ENMFP is closed source, I can't dig through the code to find the "possible leak". Anyone else experiencing this problem?