Jim Gamble, chief of marketing at Apple's huge software division, said the company started to ship Harmony three weeks ago as part of its pledge to continue improving its venerable MacOS line even as Apple rushes to produce a modern OS based on Steve Jobs' NextStep software, called Rhapsody. That's big news for Apple users and for people in the far larger Wintel world as well. Here's the deal: Apple is shipping MacOS 7.6, the so-called Harmony version of the Mac's operating system. This, as we'll see, is the case despite AOL's vexatious busy signals, lousy service and all the other problems that have plagued its once-trusting customers in recent weeks.