Threading became stable as of 5.8.5

Thread implementations previously before this would die
mysteriously if a program was doing a large number of
memory operations over a period of 24 hours of greater.

As of 5.8.5 perl was capable of handling threading for
approximately 24-72 hours (3 days) but thats honestly
kindof a vague expectation.

I actually reccomend that you design any long running
thread implementation as a state engine capable of
resuming where you left off, and when you left off.

Perl 5.8.7 seems to handle things alot more stable,
however please heed my advice regarding the state engine.