Idea 7.0.2./7.0.3 & JSDK 1.6.0_06 - can not set as JSDK in settings

fresh WinXP SP2
fresh JSDK 1.6.0_06
fresh Idea 7.0.2, than 7.0.3

Settings->General->Project JDK: ]]>, choose JSDK, select path where JSDK 1.6.0_06 installed
(in my case C:\9nt\c\jdk160_06)

I receive error box "Select Path" with message
"The directory selected is not a valid home for JSDK"

I tryed Idea 6.0.6 and the same JSDK path - all ok.
I tryed Idea 7.0.3 and C:\9nt\c\jdk142_05 and all worked ok

So something wrong with the combination Idea 7.0.x+JSDK 1.6.0_06 or with my brain/hands