When creating issues JIRA 5 only creates Bug issue type

Customer reported that when creating an issue in JIRA 5, it only creates Bug issue type.
No matter the issue type chosen, the instance automatically changes to Bug.
This is happening only with IE 8.0.6001.18702 and IE 8.0.6001.18702CO under Windows XP OS, as I couldn't reproduce it with the following environments:

*IE 8.0.7600.16385 + Windows 7
*IE 8.0.7601.17514 + Windows 7
*IE 9.0.8112.16421 + Windows 7

Follow attached a video sent by customer with the "bug in action".

Although tested in JIRA OnDemand, this might affects JIRA Standalone also.