I had (actually I still do) the same problem. I asked my ISP, and they told me it would be possible to work around these restrictions by creating a .htaccess -file. It allows you to set the max_filesize_upload, max_post_limit, max_execution_time etc by your self. Unfortunately my problems still exist, as I can't upload any files bigger than 1 meg (dispite the fact that the servers max_filesize_upload in their php.ini is 2 megs...).
Anyone experienced the same problem?