Client Admins that have the right to submit tickets for others, when they select the radio button for "Other" and type the user's First or Last name in the client lookup box, never get any result when they click search.
One thing to note there is that the Client Admin, when searching there, will only get return values if the person they are searching for is in the LOCATION or DEPARTMENT for which they are deemed a Client Admin.
So, if i am a Client Admin for ATLANTA but i search for someone else who has a Location set as HOUSTON, i will not find them.