Go to your wp-admin>settings>miscellaneous and try to see your upload folder. And also, did you recently moved your site?
yes this is a new install on a new host... it happens when i install themes or plugins or try to update... i will try what you said yuuko
Ok then let me know what happened. And also another question, are you installing it manually or via fantastico (etc..)
I suggest that you install it manually. Download the latest version of wordpress here. http://wordpress.org/latest.zip Then follow the instructions here. http://codex.wordpress.org/Installing_WordPress