Paul Kaye - 2015-06-01

Here's a strange one. Recently, instead of displaying the "context menu" (e.g. so that I can "open containing folder" of a file), when I press the tab key, the letter "a" (in a different font) is inserted into the search string.
Here's an example: I type "notes", and a file appears in the list.
screenshot1

But when I press the tab key, the "a" appears instead of the "context menu".
screenshot2

Any advice would be most appreciated!