Xperia X10 :: Does Not Pick Up All Contacts On Auto-fill When Sending A Text Message

When selecting a contact to send a message to, the drop down list auto fills with some of my contacts which start with the letters I am keying in, but it does not auto fill with all the relevant contacts, missing out most of the contacts which start with the letter or name I am keying in? E.g if I was sending to a contact called "Paul" Keying in "P" would only bring up a few of the contacts I have starting with "Paul" but no all of them Even if I continue to key in the full name the auto fill does not seem to find the exact same name which is in my contacts Is there any way to turn off this auto fill so you can manually select the contacts I wish to sent the message to?