[Plugin: Twitter Tools] twitter tools doesn't work anymore

Try this one:

http://ww.wp.xz.cn/extend/plugins/simple-twitter-connect/

I recommend asking them to upgrade to PHP 5.

PHP 4 has been discontinued since August of 2008, and WordPress will require PHP 5.2 starting with 3.2, which is due the first half of 2011.

If they refuse to upgrade to PHP 5 (which again has been out and stable for over two years), there are plenty of other hosting providers to take your business to.