I’ve had the same problems as have apparently a whole ton of bloggers. Adam Kalsey, the author of the MT plug-in, has come up with a fix, which I have installed, that at least doesn’t cause MT posting to crash when the Technorati feed goes down. He has provided a lot of free e-mail tech support for a plug-in for which he’s charging zip, so I’m giving it a while to sort itself out.
As best I can tell, SiteMeter periodically experiences a lag effect but then restores the “missing” visitor hits as it can. Its correlation with the internal logs one gets from one’s site host is rather poor, however.