Regex Help

Am attempting to use the following signing regex trigger:

(?i)(^subject :\s\[sign\]|^x-secure-sign :\strue$)

but when I review the log file I am seeing:

02 Aug 2012 09:25:03 | WARN Invalid pattern. Trigger: (?i)(^subject :\s\[sign\]|^x-secure-sign :\strue$) (mitm.application.djigzo.james.matchers.SenderHeaderTrigger) [Spool Thread #0]
java.util.regex.PatternSyntaxException: Unmatched closing ')' near index 33
\s\[sign\]|^x-secure-sign :\strue$)
The braces match so am missing why the parser believes they are unmatched ?


Thanks, Phil