Commits are not appearing in the Commit Tab for non-standard issue keys

When we specify a customized project key in a commit message, the commit will not be linked to the related JIRA issue. Please see the screenshot below:

• Commit activity in Bitbucket
  
• The commit appears in the issue TT-3
  
• The commit doesn't appear in the issue SPUSC2013-1
  

Steps to reproduce:

• Modify JIRA project key pattern to ([A-Z][A-Z0-9_]*)
• Make a test commit with the custom issue key in the commit message
• Synchronize the repository in JIRA
• Access the related issue, and open the Commit tab