Reintegrate woes

We have been working for a long time (almost a year) on two products in paralell. One is a maintenance product, i.e. general bug fixes and very little new features, called "base" and is effectively trunk. The other is a "new and improved" with all the latest bells and whistles, and is handled in a branch. Both of them are divided into ca. 80 sub-products, 10% unique and 90% common, of which roughly 20% of the latter are branched.

As both teams progressed they fixed bugs or added features in their respective product, hence it was necessary to merge both from branches to trunk and vice versa.

Now comes the time to merge branches back to trunk and I try with a:

ft_at_halt:/proj/.../ecom_spu>svn merge --reintegrate file:///home10/svn/.../ecom_spu/branches/foo .

Sometimes this works as expected, but on most occasions I get:

svn: Reintegrate can only be used if revisions 1413 through 2204 were previously merged from file:///home10/svn/.../ecom_spu/trunk to the reintegrate source, but this is not the case:
  ecom_spu/branches/foo
    Missing ranges: ecom_spu/trunk:1413-1707,1709-1852,1854-1855

I take it that meas that svn has detected that something has gone from branches back to trunk on an earlier occasion? Isn't it really necessarry to break "reintegrate" like this? svn has all the relevant information of which revisions have gone where. And I can perform the merge by doing:

ft_at_halt:/proj/.../ecom_spu>svn merge -r 1413:2204 file:///home10/svn/...ecom_spu/branches/foo .
--- Merging r1414 through r1422 into '.':
U ecom_edhipc_decl.ads
U mtt_gateway.adb
--- Merging r1424 through r1527 into '.':
G ecom_edhipc_decl.ads
G mtt_gateway.adb
--- Merging r1597 through r2204 into '.':
U ecom_spu_1.adb
U ecom_spu_socket.ads
G ecom_edhipc_decl.ads
U ecom_spu_socket.adb
G mtt_gateway.adb

Or am I missing something here?

Regards,
 -Frode

-- 
^ Frode Tennebø               | email: Frode.Tennebo_at_saabgroup.com ^
| Saab Technologies Norway AS | Isebakkeveien 49                   |
| N-1788 Halden               | Phone: +47 45 24 99 39             |
| with Standard.Disclaimer; use Standard.Disclaimer;               |