Spanning Tree Problems with Access Points connected to Procurve Switches

Anyone ever find switchports flapping on an off when Spanning Tree is active and an access point (7055, 7363, 7372, 7962) is connected? We have found this in several properties now with very similar configurations but have not been able to determine a cause. All of our hotels use Procurve switches at the edge (2910al-PoE or 2520-8G-PoE), all participate in spanning tree, but we only observe the flapping on about 1% of switchports. Of course, 1% for us means that 10-50 guests are getting knocked off the network regularly, so it is a bit of an issue (some ports have 200-300 state transitions *per day*.
We have verified that the configurations on the ports that have the problem match the ports that do not with regard to BPDU filtering, root-guard, etc. We do not believe that it is a deliberate attack because it is the same access points that have chronic issues, whereas the other 99% never do.
Any ideas?