In IE 8, when adding a new story, the MRU drop-down for the "As" field does not let you pick the first item in the list when nothing is picked so far. The workaround it to pick a second or third item on the list, then wipe it out and pick the first item.
Steps to reproduce:
1. Create two initial stories with "As a user" and "As a super user", so that "a user" and "a super user" will be in the MRU.
2. Create a third story and type the letter a into the As field. The MRU should drop down with "a user" and "a super user" in the list.
3. try to pick the first item - you can't.
4. Pick the second item.
5. Backspace over what got entered back to the letter "a"
6. Now you can pick the first item.