Problem with gplink/gpasm and UDATA

Hello,

Here at Cambridge University Engineering Department we are big users of 
open-source software.  As such I am looking at setting up a PIC 
development environment using anjuta, gputils and sdcc.

At the moment I am struggling with gplink & gpasm.  I can't seem to get 
gplink to link any object file that was compiled from an asm file with a 
non-absolute UDATA section.  If I include an absolute memory location 
(as in sec_name UDATA 0x20 instead of just sec-name UDATA) then 
everything works fine.

I expect I am missing some fundamental point but I cannot for the life 
of me work out why this doesn't work as I am fairly sure that the 
location part is optional.

I'm using gputils v0.13.2 which is installed in /home/ajg72/picdev 
(rather than /usr/local) and I have /home/ajg72/picdev/bin in my $PATH.

I am using the following commandlines:
gpasm -c simple.asm
gplink simple.o

simple.asm looks like this:
;-----------------------------------
	list	p=16f873
	radix dec
	include "p16f873.inc"
	__config 0x3fff

	
data_sec	udata
fred	res	1


STARTUP	code

start	nop
	goto	start

	end
;------------------------------------

gpasm reports no errors, warnings or messages but gplink outputs:
message: using default linker script 
"/home/ajg72/picdev//share/gputils/lkr/16f873.lkr"
error: linker script has no definition that matches the type of section 
"data_sec"


thanks in advance for your help,
Anthony Green - [email protected]