Reproduction steps:
1. Goto calendar list, click an calendar item
2. In calendar item view, click 'Show detail'
3. Click the hyperlink in detail view
4. Go back to the calendar list and click same item again
5. Click the hyperlink again
Reproduction steps:
1. Goto calendar list, click an calendar item
2. In calendar item view, click 'Show detail'
3. Click the hyperlink in detail view
4. Go back to the calendar list and click same item again
5. Click the hyperlink again
