FYI... we have used the <> and the NOT LIKE statements,
I had the exact same problem! I'm was using Queries to define target computers for a software distribution task and I wanted to filter out some OU's. I had a long list, but as example, I wanted to exclude OU "BabyAssistedBreathing" and OU "ProctologyExamScopes" because I sure don't want those to reboot or have an "oopsies" accidental service disruption.
In the query it looked like this:
AND ("Computer"."LDAP Location" Not Like "BabyAssistedBreathing"
AND "Computer"."LDAP Location" Not Like "ProctologyExamScopes")
I had used an OR between the "Computer"."LDAP Location" before and it just wasn't logical. Won't work right with the OR. Since a vulcan wasn't around, it took me a while to figure out what was going wrong.
Thanks benjones. This has saved me much time in my work efforts.