Zenphoto 1.2 tag searches require exact match of the tag. This was an artifact of changing the tag implementation to a table structure for efficiency. So if your tag is `flor flower` then that is what you must enter for it to be found. Of course, you could have made two tags, `flor` and `flower` which really would have been a better choice.
With zenphoto 1.2.1 (and the nightly builds, we have found a way to make partial match searches work with the new tag structure.)