I found the rule that, in 2002, was interpretted as requiring reissue and recalculation of fare for a change in the first international departure from Area 2. The rule is ambiguous but my argument that it draws a distinction between Area 1 which requires reissue and Area 2/3 which do not require reissue fell on deaf ears then. Perhaps the airlines have reinterpretted this rule now; I hope so. Here is what it said then, quoted in full (ie. there were no additional rules specifed for Area 2/3):

21N CHANGES/ NOTE -
22N . FARES TICKETED AND ORIGINALY ISSUED
23N . ON/BEFORE 31MAY02 AND REISSUED ON/AFTER
24N . 01JUN02 MAY INCLUDE SECTORS FLOWN ON DI.
25N .
26N . 1.PRIOR TO DEPARTURE
27N . TRAVEL ORIGINATING AREA 1 -
28N . - BEFORE TKT DEADLINE - PERMITTED WITHOUT
29N . PENALTY. CHANGES TO THE 1ST INTL FLT OR
30N . PRECEDING FLTS REQUIRE TKT REISSUE.
31N . - AFTER TKT DEADLINE - CHANGES TO THE
32N . 1ST INTL FLT AND PRECEDING FLTS ARE NOT
33N . PERMITTED. DATE/TIME CHANGES TO OTHER
34N . FLTS PERMITTED AT NO CHARGE. TKT MUST
35N . BE REISSUED.
36N . - CHANGES OTHER THAN DATE/TIME PERMITTED
37N . FOR USD75 PER TRANSACTION. IF THE
38N . CURRENCY OF TICKET ORIGIN IS NOT USD,
39N . CONVERT THE USD AMOUNT AT THE BSR.
40N . TKT MUST BE REISSUED.
41N . - CERTIFIED DEATH/ILLNESS OF PSGR, PSGRS
42N . IMMEDIATE FAMILY OR ACCOMPANYING PSGR,
43N . REROUTING PERMITTED FREE.
44N . TRAVEL ORIGINATING AREA 2/3
45N . UNLIMITED CHANGES PERMITTED WITHOUT CHARGE.