With NetBeans 7.0 beta it looks like if you have a ~endless loop causing an exception for you, then when you click on the report the problem button, the new window is showing up, but the next exception will steal the focus from the reporter window... This makes really hard to send a report with a decent message. The report sender window should own the focus, while sending report, so subsequent exceptions won't steal the focus from it.
well, this is not related only to 7.0 beta, it works like this for ages. Problem is that it's a feature of NetBeans dialogs API that each time dialog is displayed, it gains focus. The only possibility is to do some dirty workarounds in exception reporter window.