Copy Issue button not functioning when JIRA integrated with Crowd

Copy Issue button ( using JIRA to JIRA Copy plugin 3.2 ) not functioning when you try to do a Remote Issue Copy you will get the below exception if one of the comments is owned by an invalid user (removed).

2013-07-01 21:33:53,490 http-bio-8081-exec-25 ERROR admin 1293x1524x1 f1po3e 0:0:0:0:0:0:0:1 /secure/CopyIssueToInstanceAction.jspa [atlassian.cpji.action.CopyIssueToInstanceAction] NegativeResponseStatus(ERROR_OCCURRED, errors: Errors: {reporter=The reporter specified is not a user.}
Error Messages: [])

The problem is reproducible when the following criteria's are met:

• JIRA is integrated with Crowd.
• The issue has existing comments and one of the comments is owned by an invalid user (removed).
• The valid user perform the action (COPY) locally from Project A to project B.

Steps to reproduce the problem:

1. Setup a new JIRA 5.2.11 and integrate it with Crowd.
2. Install JIRA to JIRA copy plugin 3.2
3. Create 2 projects - Project A and Project B.
4. Create one issue in project A.
5. User A comment on it and configure the user A become inactive in Crowd directory. After that, sync the user directories in JIRA.
6. Logged in as admin user to copy the issue by click on Remote Copy more action -> remote copy
7. After click next button to select project -> update details -> confirmation operation page.
8. Try select internal or valid user for Assignee and click Copy Issue button but JIRA do not redirect the page or shown any success message.
9. The following error shown in JIRA log:

   2013-07-01 21:33:53,490 http-bio-8081-exec-25 ERROR admin 1293x1524x1 f1po3e 0:0:0:0:0:0:0:1 /secure/CopyIssueToInstanceAction.jspa [atlassian.cpji.action.CopyIssueToInstanceAction] NegativeResponseStatus(ERROR_OCCURRED, errors: Errors: {reporter=The reporter specified is not a user.}
   Error Messages: [])