Silverlight SaveFileDialog doesn't work in Opera

Generally, most Silverlight 3 applications work ok in Opera. There were some problems with windowless mode in Opera using Silverlight 2, but it appears that it's been fixed in Silverlight 3.

Nevertheless, Opera is still not on the list of Microsoft Silverlight 3 officially supported browsers, and today I've found one more reason why. There isn't much documentation about this stuff, but I've got an exception when Silverlight 3 SaveFileDialog is used in Opera 10 (build 1750). The thrown exception is:

"Dialogs must be user-initiated at System.Windows.Controls.SaveFileDialog.ShowDialog()..."

which appears in other browsers, too, but only if you try to invoke save file dialog avoiding button click event. I haven't found any workaround for this, so my code looks like this. I would like to know if there is a better way to solve this problem in order to use Silverlight applications in Opera. Any thoughts?