how can it merge revisions committed before the branch was forked?

Colleagues,

I created a branch by running "svn copy trunk branches/FOO" in my
working copy and committed the new files, which created revison 3053.
Then I modified some files in both locations. When I run "svn
mergeinfo" in branches/FOO, it shows the following revisions for
merging:
r3041
r3051
r3054
r3055

Why does it suggest merging revisions which were committed before
branches/FOO was even forked? When I tried to merge nonetheless, some weird
conflicts arose. Have I done something wrong?

-- 
Victor Sudakov,
VAS4-RIPE, VAS47-RIPN sip:sudakov_at_sibptus.tomsk.ru