Strange problem on IE9, not able to type in any fileds

Hi,

We have just recently moved from TS 2003 to RDS 2008R2 (last week in fact).

All of a sudden today (Monday of course), users are having issues on IE9.

They can use it OK for a while but then when using any site that has a field to enter data, it won't type, i.e. they bash away at the keyboard but nothing comes out.

Occasionally, an IE menu will open corresponding to the letter typed (e.g. type a 't' and the Tools menu opens). This is only happening on IE though, not on Windows itself.

I really don't know where to start with this so I thought I'd ask you guys and gals.

Seen this before?

Thanks in advance.