The Microsoft Internet Explorer forgets the setting of the actual Theme.
It does not have anything to do with custom themes.
1. Set the theme to "pods_summer" with anything other than IE.
2. Connect to your JasperReports Server with IE and the theme should be the green pods_summer
3. Hit the refresh button of IE and the theme looks like the default one.
In settings pods_summer is still active, but obviously not shown.
Would be glad, if you could fix that. Maybe you already fixed that in 4.8 ?