Something Keeps Asking for my SSH Key

[WhatUsernameIsFree?]

Hi all,

My desktop computer keeps popping up a box asking for my SSH key. If I click cancel, then it will ask for it again approximately every 5 minutes. Is there any way to find out what might be asking for it? I've not installed anything that isn't from a repository recently and the only thing that has changed is the installation of Sparkleshare, which uses its own unencrypted key.

Thanks