Do you know any resource describing in detail Qt SDK folder structure?

For example, I'm wondering why some of dll files are in c:\qt\2009.03\bin and in c:\qt\2009.03\qt\bin at the same time? Having the same name they have different sizes (QtCore4 - 2*016*256 bytes in the first folder and 2*730*496 bytes in the second folder). What's the difference between dll files with the same names in both folders?

SDK default installation path is c:\qt\2009.03 and qt ends up being installed in c:\qt\2009.03\qt. Shouldn't qt be rather installed in let's say c:\qt-4.5.2 instead? Can I split SDK's qt from the rest of SDK and point SDK to the new location of qt?

Thanks in advance for all replays.