We have actually seen this on our hosts too. What's pecuilar is that this patch is for going from 4.0 to 4.1 even though our hosts have already been updated to 4.1. (4.1.0, 320092 to be exact).
This notice appeared after we did a second round of patching at the beginning of this month while our move from 4.0 to 4.1 occurred several months prior.
We've seen the same behavior. We had upgraded the hosts to ESXi 4.1 from 4.0 u1 and in January had gone back to patch with the three patches that had come out since November. After patching, only one of the servers in a cluster had this error but we haven't seen any performance issues yet.
To round out our issues with this: after a few reboots for various reasons, all of our hosts are now showing this issue. Discussions with the support team seem logical in that this is now an outdated baseline and should be detached. No performance issues were found and no negative entries have been found in the logs (either by us locally or by the VMWare support team).