[otrs] Customer user drop-down

I currently have approximately 400 - 500 customer users in my database. When an agent tries to open a phone ticket, however, it appears that only 150 of these users appear in the user drop-down menu. I'm not sure why this is being capped. Is there any way to remove this limit? Christopher J. Peterson Compulit, Inc (616) 285-9590 cpeterso@compulit.com