The Latitude D610 is the upgraded version of the Inspiron 600m. It is much stiffer, has a better keyboard, but is also slightly thicker.
The Inspiron 600m is based off of the Latitude D600 which is no longer available.
Well, everyone is human... it is conceivable that the IBM technican forgot to put everything back into your system when they serviced it. I haven't heard of it happening to anyone before, but it is possible.
However, I have heard of...