Hello Sepideh and Gary,
I think this is duplicate of BAM-12043 which was fixed and released in 4.4.5. Can you check that somehow (like for example set up a test Bamboo 4.4.5 instance and wire it up with Trac via "Web Repository" configuration?)?
One thing that is worth to check prior: what happens if you hover mouse over the "revision" field (in the Build Result Summary pages, left of the 'copy to clipboard' icon)? Will you see 'title' being popped up with a messsage _"Unable to create URL - please check your Web Repository configuration"? If so, I'd strongly suggest to upgrade to 4.4.5, as that would mean it is a duplicate of BAM-12043 for 99%.
regards,
Piotr Stefaniak
Bamboo Developer
Closing this as comment on
BAM-12043explicitely confirms that linking to Trac has been fixed.