"Profiled process terminated. Profiler connection not establ

"Profiled process terminated. Profiler connection not establ

I tried to switch from NCover 1.5.4 to 1.5.7. Here is what I did

Installed 1.5.7
Copied the resulting files into our SVN repository over the old ones (i.e. 1.5.4)
Did the same for ncover explorer and their nant tasks (1.3.6)
Uninstalled 1.5.7 to be sure it used the ones in the repository.

Ran our NAnt script.

Everything worked fine.

Committed, and on our build servers, all of them reported:
"Profiled process terminated. Profiler connection not established. "
after running the first test.

Anything I'm missing? anything I could check?

To my knowledge, there is a DLL that should be registered, but the NAnt task does this so I should be ok.

Checked in the GAC, and not trace of NCover, not on my machine, not on the dev server.

Any help appreciated.

nick