To reproduce:

Create up a Hudson multi-configuration job, called "Test Job 1". In the Configuration Matrix check "Axes" and
enter e.g. "CLIENT" in the "Name" field and "foo bar" in the "Values" field. In the build steps, add an "Execute shell"
step and enter a simple shell script, e.g. "echo `date` $CLIENT > dummy-artifact.txt"-

Create a new Hudson job, called "Test Job 2", by copying "Test Job 1".

Go back to the configuration of "Test Job 1", and under "Post-build Actions", check "Build other projects", and enter
"Test Job 2" in the "Projects to build" text field. Save the configuration.

You will now see that "Test Job 2" is a downstream project of "Test Job 1".

Click "Build Now" of Test Job 1 to test the build triggers. Both configurations of Test Job 1 should be built, and then
both configurations of Test Job 2.

Now, go to the Configure page for Test Job 2. Verify that under "Build triggers", "Test Job 1" is listed under "Build
after other projects are built", but don't touch this value. Instead, go to (for example) the Description field there
and write anything. "Gazonk" is a good value. Click "Save".

EXPECTED RESULT: The description of "Test Job 2" reads "Gazonk". The main page of "Test Job 2" still lists "Test Job
1" as an upstream project, and the main page of "Test Job 1" lists "Test Job 2" as a downstream project.

OBSERVED RESULT: The description of "Test Job 2" reads "Gazonk" as expected. But the build
triggers/dependencies of "Test Job 1" and "Test Job 2" are gone. From now on, building Test Job 1 will not trigger a
build of Test Job 2, even though the only thing that was changed was the Description field of Test Job 2.

Re-adding "Test Job 2" as a downstream to "Test Job 1" solves the problem, but the build trigger goes away the
next time the configuration of "Test Job 2" is changed (but NOT when the configuration of Test Job 1 is changed).
Description was chosen as an example here because it should be unrelated to most other configuration items, but
the problems happen with other (if not all) configuration fields as well.

Reproduced on Hudson v.1.311 (Linux) and v.1.314 (Mac OS X)