mercantec_softcart exploit problem

[rhg_xu at 163.com (rhg_xu at 163.com)]

Hi,
Anyone can help me? I try metasploit3 which svn co on February 25,2007 mercantec_softcart exploit, exploit execute 
successfully, but doesnot send efficient packet( only syn ack session established packet), I tracked it, in 
lib/rex/proto/http/client.rb, I locate "req_string = req.to_s;ret = conn.put(req)" execute not succ, I modified it to 
"ret=conn.put(req_string)", but cannot send http get packet, I assure exploit code include in "req_string" variable by 
print it to console, I try define a variable "ttt="helloworld";ret=conn.put(ttt)", but this successful which I got 
efficient packet(http header), I think it must wrony something, but I donot know the key point, please help me, thank 
you again . :)

tom