I applied all fixes. Unfortunately I still see in access log theese long links like

75.150.10.62 - - [30/Sep/2008:12:14:32 +0400] "GET /skandaloff464?CmtText=pharmacy%3B+http%3A%2F%2Fleto2005.variant.lv%2Fforum%2Ftopic.php%3Fforum%3D1%26topic%3D239998+soma%3B+http%3A%2F%2Fglebka.ru%2Fforum%2Fviewtopic.php%3Fp%3D314517%23314517+soma%3B+http%3A%2F%2Fantichp.mypressonline.com%2Ffor .... +soma+usa%3B+&CmtParent=0 HTTP/1.0" 200 37060 "http://samaroid.ru/skandaloff464" "Mozilla/4.0 see more (compatible; MSIE 6.0; Windows NT 5.1; SV1)"

I tried to ban IPs in .htaccess file but it's impossible to do it every day. I'm thinking now to change webhoster company...