CPPUNIT_ASSERTs cause system to freeze or hang

Without providing too much context (as I have seen this issue in many different unit tests) can anyone explain to me why a failing CPPUNIT_ASSERT call will sometimes cause the program to freeze/hang?

For example, I will often use a test program wherein I will see the call...

CPPUNIT_ASSERT(condition);

This call of course will ideally do nothing if condition evaluates to true, or incite a crash and print a statement indicating that a failure occurred at this assert. My problem is that sometimes, these asserts will cause the program to hang when condition evaluates to a false.

I have seen numerous functioning tests wherein fails will behave appropriately, but now and then tests I use end up having this issue. This becomes obnoxious as it requires me to debug code just to figure out a test is failing when it should. Has anyone else seen this issue or can anyone provide incite as to why this might be occurring?