Filtering results by username - Ajax trim() issue

When viewing node/%node/results for a quiz the user can filter the results table by entering a username or part of it.

But we have use cases where the user selects the username and presses space to delete. For the user it seems the textfield is empty, but actually it has a space in it. The result is a blank table of results.

The ajax call to filter the table, should make use of trim() to remove start and end spaces. Marking this as a major bug as it causes major problems for some users, and most of all because Quiz remebers the filter from page load to page load.