New Developer Console warning in 5.1d "already observing method 'ruleContextChanged'"

[Blama]

Hi Isomorphic,

I'm getting a Developer Console warning in 5.1d (SNAPSHOT_v10.1d_2015-07-21) I'm not getting in 5.0p (v10.0p_2015-07-15).

Do you have an idea what could be causing this?

11:34:34.972:XRP0:WARN:ListGrid:ListGrid_inCreation:Observer:[ListGrid ID:ListGrid_inCreation] is already observing method 'ruleContextChanged' on object '[VLayout ID:isc_LMSSectionStackSection_1_0]', ignoring

It happens in FF26 and GC43 (did not try IE11).
"ruleContextChanged" is not something that rings a bell w.r.t. my code.

Best regards
Blama

[Isomorphic]

We didn't reproduce the error, but we added a guard that should prevent this double-observation. Fix will be in the next build.