Mousewheel zoom makes page scroll only with Bing Maps enabled in switcher

Hi there,

I made a lucky/odd discovery regarding the issue that if you use mouse wheel zooming the whole page might scroll down while zooming. It comes down to whether you enable or disable bing maps.

How to reproduce the bug:
- in the LAYERS & STYLES section in the OpenLayers map configuration enable any Bing Map, so it is choosable via the top/right menu
- in the behaviour section in Navigation enable "Enable Zoom Wheel"
- click save and go to the map
- using the mouse wheel for zooming in/out makes the page scroll

- now go back to LAYERS & STYLES and disable any bing map
- check out your map again, zooming in/out with the mouse wheel doesn't make the page scroll anymore

This was tested with Firefox 25-28, Chromium 30 and Chrome 31.
For the record: I haven't acquired an API key for BING maps, if this happens to be the reason, the issue might be more general and not only connected to Bing Maps.

Even if this isn't considered a bug, maybe this info helps someone out there :)

Cheers,

hsiyao