This is almost certainly a dupe, but I don't have a record of it: I built on mac os x 10.4.6 and got warnings about the heartbeat frequency, e.g., ./mix > test6.out 1.374983 secs elapsed cpu time heartbeat frequency = 48.72787518100223 Hz *** possible problem: expected heartbeat frequency = 100. Hz Reporting, as a just-in-case. Brian