I was sending out some emails this morning, and while using spell check I noticed something strange: my "Add to Dictionary" button was grayed out!?!

First thought: this cannot be! I love that button!

Next thought: check what's going on with my custom dictionary. So I checked out the options panel under the office button (in Outlook 2007.)

Under "Proofing", there is a "Custom Dictionaries…" button:

Next step: check my custom dictionary path… uh, where is my custom dictionary – and its path?

Next step: use the "Add…" button to add the custom dictionary back to the list. Fortunately, it defaulted to the appropriate path:
C:\Documents and Settings\<username>\Application Data\Microsoft\UProof\CUSTOM.DIC

Problem: after adding the dictionary to the list and closing the "Custom Dictionaries" dialog, I checked the list by reopening the dialog – nada… it disappeared! Outlook wouldn't let me add the custom dictionary back to the list.

Solution: restart outlook. After the restart, everything works perfectly.

Weird.