X-Pad: avoid browser bug" header you should feel lucky. The
X-Padheader is a work around Apache uses for a bug in really old versions of Netscape and it only shows up if there's a chance the 256th or 257th byte of a response is a newline.
It's a junk header, all it does is prevent the 256th and 257th byte of the response from being a newline. If Apache didn't do this, old versions of Netscape would hang.
It's a wonder why this is still part of Apache, we're talking really old versions of Netscape here.