cache lookup error when excuting function

Hi folks,

first I want to say thank you to all the people given me tips on
how to get triggers start a function - you where very helpfull.
But now I have another problem which I don't understand at all. I
created a function in plpgsql which sets my current date, time
and user. It looks as follows:

CREATE FUNCTION fncdatetime_ains() returns opaque as
'begin
new.TimeStamp := now;
new.C_Date := date;
new.C_Time := date;
new.C_User := getpgusername
end if;
return new;
end;'
language 'plpgsql' \g

Then I created a trigger on a table executing this function on insert:

CREATE TRIGGER trgInsServer after insert on tblserver
for each row execute procedure fncdatetime_ains() \g

Now when I do an insert into my table from a website (using php4 pl01)
I get the following error:

PostgreSQL query failed: ERROR: fmgr_info: function 69056: cache lookup failed

What does this mean???

Please all, can you help me again, this is quite important for my project

chris