Convergence and ReplaceAll

[Chip Seraphine]

I am attempting to ensure that a given setting in a file is always set to a 
particular value; specifically, I want my coreadm.conf file to contain the line

        COREADM_GLOB_PATTERN=/var/core/core.%f.%u-%p

This is to replace any existing COREADM_GLOB_PATTERN line, or add a new one if 
none exists. Here is the editfiles block I am using to do this:

{ /etc/coreadm.conf
        BeginGroupIfNoMatch 
"[[:space:]]*COREADM_GLOB_PATTERN=/var/core/core.\%f.\%u-\%p$"
                ReplaceAll "^[[:space:]]*COREADM_GLOB_PATTERN=.*$"
                  With "COREADM_GLOB_PATTERN=/var/core/core.%f.%u-%p"
        EndGroup
        DefineClasses "run_coreadm"
}

The problem is that I am getting this result:

        cfengine:mingle: WARNING: Non-convergent edit operation ReplaceAll 
[COREADM_GLOB_PATTERN=/var/core/core.?f.?u-?p] With 
[[[:space:]]*COREADM_GLOB_PATTERN=.*$]
        cfengine:mingle: Line begins [COREADM_GLOB_PATTERN=]
        cfengine:mingle: Replacement matches search string and will thus 
replace every time - edit was not done
        cfengine:mingle: Error editing file /etc/coreadm.conf

I would understand this if I didn't have the BeginGroupIfNoMatch block.  Is the 
problem that the interpreter doesn't realize the Group stuff protects us from 
nonconvergent behavior, or am I just totally misunderstanding something?  And 
how does everybody else deal with this sort of problem?