search tags not working

Hello search by tag isn't working and I have many tags on my site. Search by nickname works though. Now if I put a nick name in the field for search by tag it works but if I put a regular tag from a photo or a blog it won't won't find that tag. Is anyone have any ideas why this is dong this. Search by tag only works if I put a nickname in the field??

Which Dolphin version are you using ???