I deleted login_up.php3, and can't recover - Help!

[soaptray]

Long story short, the file /usr/local/psa/admin/htdocs/login_up.php3 has been changed, causing domain.com:8880 to throw errors.

I tried to copy a fresh file to the directory, and give it the same owner / group as the other files, and still I get the error.

Any help would be appreciated.

Thanks.