size discrepancy

[JD]

$ ls -l
total 7070588K
-rw-r--r-- 1 jd jd 3616604160 Oct  1 23:27 f14.iso
-rw-r--r-- 1 jd jd       1602 Sep 29 20:35 Fedora-14-Beta-i386-CHECKSUM
-rw-r--r-- 1 jd jd 3616593920 Sep 29 21:56 Fedora-14-Beta-i386-DVD.iso

I burned Fedora-14-Beta-i386-DVD.iso to blank dvd.
One time I used wodim, and 2nd time I used growisofs.
After each burn, I would dd the dvd back in:

dd if=/dev/sr0  of=f14.iso bs=2k

In both cases the size of f14.iso was 10240 bytes larger than
Fedora-14-Beta-i386-DVD.iso.

So, naturally, I will not be able to get the same sha256 sum
as that of Fedora-14-Beta-i386-DVD.iso

So, how do I dd the dvd in and get the same size as original iso?

Perhaps growisofs and wodim are padding during burn.
If that is the case, how do I suppress it?