Safari under Mavericks. window open but not selected nor visible
I have a problem in Safari on an iMac running Mavericks. I select New Window. No window appears. If I select Window, then I can see at the bottom of the menu Untitled but no check mark. So I click on Untitled and a small window opens. then I have to click on the green button at top left and the window opens to what I expected all along. This problem is happening on my 2 year old iMac but not on my wife's 4 year old Mac Book Pro. The problem appeared as soon as I did the upgrade from Snow Leopard to Mavricks on the iMac. It has not happened on the Mac Book Pro. I tried Reset Safari and that did not help. I hate to unlock the iMac from its cable and then schlep it out to the car, over to the nearest Apple Store and in to the Genius Bar. Might have to but maybe someone has a flash of insight.
27" iMac, Mac OS X (10.6.4)