Internet problem.

I am having terrible problems with the internet connection at school. This is stopping me from uploading my work to my blog. Also I am now wanting to carry on with my story boarding for my music video but I can't because the internet connection won't work for the websites I need which is grooveshark.com to listen to the song I am making my music video for. Although those websites do not work I am finding that blogger.com is working which is quite strange, so I am thinking it is only certain websites which arn't working on the school computers. This is frustrating as I need to use the internet a lot in my media work for my blog, which is stopping me from doing as much work as possible at school so instead I have to do it at home where there isn't any physical help from the teacher if I need it.