On the latest and greatest Chrome version (updated today) there is some wonky behaviour in the Grid filter.
I've created a dojo script to show the issue http://dojo.telerik.com/ipihu
To see the issue, follow these steps
1 -On the ProductName column, click the menu button to see the column menu
2 - On the Filter sub menu, move your mouse to the right
3 - In the filter menu, hover your mouse over the text area (just below the Is equal to)
4 - The filter dialog goes away
The issue is #4. It shouldn't go away because i'm still hovering (intending to type something in)