magento mass catalog reindex problem

i have just imported 300,000 products and i can see them fine in the backend however i cant see them on the frontend because of the indexing, i have tried to refresh the indexes on magento reindexing option. However it seems to halt on the catalog_category_product_index table and nothing actually gets indexed. If i clear most of products and leave 200 items and try to reindex again it works fine and catalog_category_product_index starts to fill up with data. I have waited hours and hours and still not working, I though it may be because it is so many products but i have a fast dedicated server with 16gb ram and i have increased all the timeouts and limits to the max. Im not 100% sure if this IS a bug, so please accept my apologies if I am doing something wrong? Who can help me.