The result shown on your screenshot might happen if KeepInScreenBounds is false and it is true in the definition you have provided. However I also see that your RadWindow should have 360px width but it has less width (300, which is the default). That is why I assume that you might have another RadWindowManager which does not have KeepInScreenBounds set to true and the window is actually created by it.
Generally, the RadWindowManager control is designed as singleton and there should be only one instance of it on a page. If you have more managers in the resultant page (e.g coming for user controls, master page, etc) this should not impact the performance significantly but only one of the managers will be "active", depending on the manager's creation time. As a result, if you want to call methods as radalert, radopen, etc the active manager will execute them with its settings. We recently provided the ability to close these methods as methods of the manager client object and this would fix the problem explained above and makes the usage of multiple managers possible. However, since the initial intend was different, I recommend to use only one manager despite this. Usually, the manager is put on the main page or the master in order to enable radalert, radconfirm, etc for all pages and in user controls and content page - separate RadWindows are used (you can use a separate RadWindow without a manager and there is no limitation of their number).
This being said, I recommend to use only one RadWindowManager and separate RadWindows on other code segments. However, if you prefer to use multiple managers, you should not call methods as 'static' but as instance methods, e.g rwm.radopen instead of radopen.
I hope that my reply is detailed enough and helpful, let me know how it goes.
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