disk corrupt d:

D: is your memory stick. The best way to fix this is to re-format your memory stick. If the phone won't boot up far enough to let you do that, take the memory stick out, boot the phone up, go to the control panel and find the format utility and THEN insert the memory stick.

And if THAT doesn't work, you'll need to format it using a card reader.

I too have the same problem with my p900. there is some problem in the phone because my friends p900 reads the memory stick which mine did not. so trying formatting the memory stick won't serve any purpose. is there any way to sort out the "disk corrupt d:" problem in p900?

There is another possibility of the corruption of the disk d:

Please check your memory stick type. P800 & P900 only support "Memory Stick Duo" and it does not support "Memory Stick Due Pro". This is first reason why you may get the "Disk Corrupt" error.

I has face this problem before.