TOPIC: Blank page *URGENT*

Hi, i need help,
Im trying to put JoComment to work, i've tried in 3 sites, and the link to the component, when i click it just shows a blank page.
In the backend all works fine.
Im using jooma 1.0.15 with JoomSEF.
Please i really need this working.
Thanks

ps: i've tried another comment component and its the same problem

what error are you getting? can you check the logs too.