asterisk users - May 2007 - 1.2.x -> 1.4.x upgrade: dialplan block no longer works

Hi,

a block of my extensions.conf no longer works after upgrading from 
1.2.17 to 1.4.4. I have:

	[macro-dialout]

	exten => s,1,Gosub(s-${ARG1},1)
	exten => s,n,Congestion
	;; default
	exten => _s-!,1,Gosub(s-NET,1)

When calling that macro whith no argument ($ARG1 empty):

	exten => _0[1-9]XXXXXXXX,1,Macro(dialcapi)

The call is not routed. Apparently "_s-!" does not match
"s-":

	-- Executing [0145201798@admin:1] Macro("SIP/0146472130-0821fe08",
"dialcapi") in new stack
	-- Executing [s@macro-dialcapi:5] Gosub("SIP/0146472130-0821fe08",
"s-|1") in new stack
	== Auto fallthrough, channel 'SIP/0146472130-0821fe08' status is
'UNKNOWN'

Any idea why?