IE9 with ArcGIS API 2.1

[DeeptiVB]

Hello:
I have a Silverlight 4.0 app running fine in IE8, FF 3.x etc. But one of  the users who is using it on IE9(the only one who uses it on IE9) has a  problem zooming with mouse-wheel. Whether the user scrolls the mouse  wheel up or down, it always zooms out. The user is unable to zoom in using the scroll wheel. Is it a compatibility issue of IE9 and the version of ArcGIS API I am using(2.1)?

Thanks,
-Deepti

(REPOST FROM ARCGIS-SERVER-REST FORUM)

[dotMorten_esri]

This is the first I hear about this. I use IE9 daily and haven't noticed this issue.
Could you possibly try making a very simple app that uses the MouseWheel event on a simple element (like a filled border or something), and in the event handler output the WheelDelta value to a TextBox. Then compare what values are outputted on your PC vs. on his, and see if they significantly differ. That might give us a first idea on what is going on. I have seen some mice send very different values to the browser, so sometimes it's also a hardware issue (although these issues should have been resolved).

[DeeptiVB]

It was an issue with the user using 64bit IE9. Thanks for your reply.

[ChristopherHill]

Silverlight will not run in IE9 64 bit mode.