Ok, finally I was able to figure out the mystery behind the crashes!
For the record, all you need to do is to start the MediaPortal Configuration, and then click on Television, and then click on TV Client. You will see a text box for Hostname. Enter the name of your computer here. That's it. Close the window by clicking OK. Now run MediaPortal and it should run perfectly. Looks like it tries to establish some sort of connection to the host mentioned in this text box and it crashes because there is no string there.
Developers: It is nice to validate the values before using them, particularly if it is a user input. Better yet, if this text box can be populated with the computer name by default.
Alas! It runs now, but it does not detect/support my TV tuner USB key!! I guess I am stuck once more.

The GUI is really impressive though.
Thanks for your help.