Wirelessly posted

I have run an assortment of 4.5 beta OS, currently 4.5.0.102. With each version of the 4.5 os I have never been able to use themes. I have made sure the themes I have downloaded are built for 4.5 I have downloaded them ota and even used desktop manager. I have down hard and soft reboots still no theme located in the themes section, however are clearly installed and visable in the app section.
Befor you say it, yes I know its beta so I know its not perfect, but I have had this issue consistantly across all versions, and I know its possiable to load themes on beta 4.5 as I have helped co works and friends update their bbs and many of them seem to not have issues with this...
Can anyone shed some light on this issue?
Thanks