This has been driving me nuts. I was using the IE9 beta on Vista 64 bit and for the life of me I could not select text from a website to copy and paste. Instead if the "I" I would get the grabby hand. I just upgraded to the IE9 RC and still I have the grabby hand where I should be able to drag and select text. Any ideas why this is happening?
In Tools > Internet Options > Advanced Tab, do a Reset, close IE then re open it.
If this is too extreme, as it will disable all your add ons and clear history etc.
Go to Tools > Internet Options > Security Tab > Internet > Custom Level button > in the Miscellaneous category, be sure "Drag and drop or copy and paste files" is enabled.