Issue keys are not hyperlinked when exporting to Excel

When configuring Issue Navigator to exclude the 'Issue Type' column, after searching for issues and export the result to Excel file, the issue links are absent, whereby the issue keys are not hyperlinked. See below screenshot:

The bug is producable only in JIRA 4.2 and 4.2.1, but the same problem doesn't occur in JIRA 4.0, 4.1, and furthermore, it is not producable in JIRA 4.2.2.