Merging trunk changes on to the Branch.

[Miller Sally S NPRI]

I have some developers(Team S) who want to make some temporary changes to the 
trunk but keep getting the updated trunk files.(made by Team P)  

so Team S does:
cvs checkout projectname
cvs rtag -b TeamS_branch
cvs update -r TeamS_branch
(they make the minor changes to branch and commits.)
(Team P will not get these changes as they are on the trunk)

Now Team P makes some changes on the trunk and commits them.
Team S wants to update their branch with these changes.

cvs update -r TeamS_branch
cvs update -j TeamS_branch -j HEAD

This seems to kill all the changes that Team S has done.

I want the new trunk changes to be added but keep the branch changes.

What am I doing wrong?

Sally