unable to edit or write

its about a year since i last published with my blog and its time to begin again. looking again though i straight away noticed that the content of the last post i made has disappeared. i have tried to rewrite it but when i press save i get a blank page in my browser (firefox 2.0.0.16 on mac 10.4.11) – the same happens when i try to write a new post.

will the year of inaction have something to do with this or do i need to look elsewhere?

thanks