cURL is an advanced PHP function that allows the Link Checker to go to a page search and view the links. It then uses cURL to go to Rapidshare and the other hosts and check their alive. A lot of cheap hosts don't have or allow cURL for security but if you on their shared hosting plan on bounceweb.com then yes you can use cURL. Sometimes it may not be activated though as standard. You should check to make sure it's on/activated.

If cURL is on and working then let us know and we'll try and find another reason.