An interisting conundrum where tables have a column called "found"

I am putting together a DB that records information about a set of web
sites and how they link to one another. As one site refers to another, I
monitor the first site and then record when I find the referred site.

I have a table called sa_site like this:
ensa1.1: sa_site
Field
Type
Not Null
Default

site_id
bigint
NOT NULL

host_uri
character
varying(1024)
NOT NULL

found
timestamp
with time
zone
NOT NULL

I also have a function called add_site that adds the newly found site.

So far so good.
To test my code I wrote the INSERT statement by hand:
insert into sa_site (site_id, found, host_uri) values
(nextval('sa_site_id_seq'), 'now', 'www.endoid.net');

and everything worked fine when called from psql.

Then I added the code to my add_site function and got the following
error:
ensa1.1=> select add_site('www.endoid.net', 4, null );
WARNING: Error occurred while executing PL/pgSQL function add_site
WARNING: line 26 at SQL statement
ERROR: parser: parse error at or near "$1" at character 43

I looked and looked but couldn't find anything that could explain the
error. Then, being somewhat used to Oracle I tried renaming the "found"
column to "found_on". Oracle occasionally has discrepencies in its rules
for the naming of objects, so I thought that something *similar* might
be happening with PG. Anyways this change did work in my PL/pgSQL
function.

Could you guys figure out where a general description of "please don't
use keywords as column names even if you're allowed to at create time
because something somewhere will throw an unintellligable error" should
live on the site?

Hope this is of help,

/e