User Picker auto-complete suggestions can be incorrect

When using the User Picker in the Issue Navigator e.g. for the Reporter field, the suggestions can be incorrect.
E.g. type in "wa" wait for one second and type "ter" the suggestion can come up for "wa" and not for "water".
The response for the suggestions of "wa" can override the response for the suggestions of "water".

The user picker should discard a response for an older request.
This is also causing us problems when running our selenium tests.