Hi there Aug 2010 I purchased a D90 - recently the transfer program has stopped working as it does not recognise any photos for transfer even though I can see them and transfer using other windows applications. I ave reinstalled the software but this has not helped, Any suggetions?

I've been studying the problem for several minutes and actually downloaded the manual from the Nikon site to confirm a suspicion. With the camera software denying the transfer yet other "Windows" application are makes me believe that there is or are corrupt files on the memory card.
The Nikon D90 is a "Semi-Pro" type camera and feature packed, however if you have been deleting files and not formatting then the memory card has become saturated with empty files (deleted) what needs to be done each time you down load is format the memory card. Formatting cleans off all the old empty files, restores the memory card to a fresh medium and allows the camera and cart to communicate between each other efficiently. Also one other thing that might have happened is that the protect lock has been engaged. The camera SD card has a lock protection switch on the left upper side (with the letter facing up) this little switch need to be pushed to the top edge towards the gold contacts. I'll supply a diagram, there is also another thing is this a new memory card? if so did you format the card to the camera before you used it? Also your camera has some SD card memory capacity restrictions these are shown on page 242 of your manual.

Diagram