gawk fails on first record (remaining records are OK) if using an FS value
of anything but the default (of space).  I have generated input files and
tested with a variety of FS values and the first record ALWAYS returns the
entire record as $1 and doesn't break it down into the appropriate
fields.  Remaining records return as expected.  First record only $1 has a
value (of the whole record) and remaining fields are null.

I can duplicate this error under redhat 5.2, 6.1 and 6.2, and using a
variety of different FS values, including ":" (documented below), "/", "a"
and several other values.

Example:

input file:
cat /etc/passwd
root:x:0:0:root:/root:/bin/bash
bin:x:1:1:bin:/bin:
daemon:x:2:2:daemon:/sbin:

looking for first record:
cat /etc/passwd | gawk '{FS=":"}{print $1}'
root:x:0:0:root:/root:/bin/bash
bin
daemon

looking for 5th record:
cat /etc/passwd | gawk '{FS=":"}{print $5}'
<<--this field returned nothing except an output record seperator,
  --I would have expected the word "root"
bin
daemon