Manu in twenty-ten theme overstresses server

Love the new twenty ten theme, especially the crisp dropdown menus, BUT:
as the number of menu items grows, saving the menus overstresses the server and throws a 500 error. I have 44 items in the menu, and adding the last five has required maybe 20 or more efforts, trying to catch the server in a good mood. Nothing else in the theme or in the site causes this kind of error (at least not on a regular basis). I’ve tried the usual stuff, setting timeouts in php.ini, complaining to the ISP (GoDaddy.com) and nothing helps. I suspect there’s something in the code that’s making the server go tilt.