The paging file can be deleted at computer close down - it is a registry setting, but that setting can be controlled via Eraser.
The swap file itself can't be deleted by Eraser simply because it is a Windows file that is locked, and therefore can't be touched. BCWipe allows the user to wipe the swap file on computer startup, before Windows loads properly but that's not an adequate solution as the computer has to close down first for this to occur and therefore sensitive information may then end up on the hard drive, in freespace.
Far better to let Windows wipe the swap file at close down (I think it just blanks the file - ie writes zeros to the file) though there again will be parts of it that can't be fully wiped due to the way Windows works. This is from the Eraser help file:
"Windows NT (and 2000) has a security feature that will overwrite the paging file at shutdown. The overwriting is done by the operating system after all applications are closed so most data will be overwritten. There are small areas that cannot be accessed because they are allocated by the operating system components that are still active. You may enable this feature from the General Preferences window of Eraser."
This applies to XP and presumably Vista too.
However, if any one is worried about what may lie in the swap file and could end up on disk then the only way to ensure total 100% security is to never use a computer!