power lists - validate against underscores

In the process of wanting to clean up power lists of generic names, I am testing with underscores to exclude any name that contains two underscores. When I do that, the PL returns 0 record. When I remove that parameter, I get my 200+ records. Clearly, underscores makes it go bizzurk!

Rule Name:CSM contacts for MONTHLY STATS
Rule Criteria:
..... (kept just a few entries here)....
AND NOT JBCXM__Contact__r.Name LIKE '%Information%'
AND NOT JBCXM__Contact__r.Name LIKE '%Contact%'
AND NOT JBCXM__Contact__r.Name LIKE '%__%'