Note that the old threading model (5005threads) does not or has bad support for shared variables between threads.
Since 5.8.4 is in use on Win32, the new model (ithreads) is readily available for you. It has backwards compatibility with the old model; the Thread module has been reworked to function as a frontend for both the old and the new model. But its not complete, because the data sharing models are directly opposed, anything to do with data sharing has to be thought differently (from ActiveState ASPN).
use threads;
and when creating the thread, use
... threads->new(/&runThread, $suite);
instead of
... Thread->new(/&runThread, $suite)