merging generated conflicts which were resolved in merged branch

I have two branches of gcc-4.6 packaging for my daily builds of gcc-linaro (native and cross):

lp:~hrw/ubuntu/precise/gcc-4.6/gcc-linaro-ci-cross (named 'ci-cross' later)
lp:~hrw/ubuntu/precise/gcc-4.6/gcc-linaro-ci-native (named 'ci-native' later)

In previous week I merged lp:ubuntu/gcc-4.6 into 'ci-native' one and got some merge conflicts (which were expected). I handled them and commited (rev 72). Then I made few other commits and finally pushed branch to server (rev 76).

Today I decided to merge 'ci-native' into 'ci-cross' to get this merge and all fixes at once. So I branched 'ci-cross' (rev 82) and then called "bzr merge lp:~hrw/ubuntu/precise/gcc-4.6/gcc-linaro-ci-native". Bazaar told me that this is 'criss-cross' merge and pointed to documentation. Merge resulted in 8 files conflicted which was a surprise for me cause I expected bzr to know that those conflicts were fixed by hand already in 'ci-native' branch.

I tried "bzr merge --lca" and "bzr merge --weave" but each time I had same 8 conflicted files. Now I am wasting my time resolving all conflicts again and I am happy that I do not have more such branches.
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ApportVersion: 1.90-0ubuntu1
Architecture: amd64
DistroRelease: Ubuntu 12.04
InstallationMedia: Kubuntu 10.04 "Lucid Lynx" - Release Candidate amd64 (20100419.1)
Package: bzr 2.5.0~beta4-1ubuntu1
PackageArchitecture: all
ProcVersionSignature: Ubuntu 3.2.0-4.10-generic 3.2.0-rc5
Tags: precise
Uname: Linux 3.2.0-4-generic x86_64
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: adm admin cdrom dialout libvirtd lpadmin plugdev sambashare vboxusers video