I recently came across this problem in LR 4.4 for some reason.
When in the Library module, I can select "All Photographs" and the attribute filter of "Stars" works with no issues.
However, when I select any of the "Collections" folders and try to utilize the attribute filter, all the photos seem to disappear. Once I remove the attribute filter (in this case the 1 star or higher rating), the images show up again in the collection folder.
Here is image 1 with no attribute selected: http://snag.gy/iqXmK.jpg
Here is image 2 with 1 star or higher filter selected: http://snag.gy/TZ9cl.jpg
Any help is appreciated, this is driving me nuts!
Could you please try and create another collection, and try using the Attribute in the newly created collection.
let me know if it works in a newly created collection or not.