We have recently implemented the Signature control into our Web Forms application using the latest version of Telerik UI Controls for Asp.Net Ajax.

We are having an issue where if the signature control isn’t in the main focus when it loads (for example the control is in a tab that isn't initially the main focus) - the signature stroke is distorted.

In addition, when you maximize the signing area - it has the same distorted view.

If you paint a stroke on the canvas, then "maximize" the RadSignature-control (effectively zooming in on the control) and then paint a second stroke, you'll see that those strokes will have a different line width; the second one being bigger.

If you repeatedly maximize/minimize the RadSignature control and draw a stroke each time on the bottom of the canvas, then the resulting image will get distorted.

If one opens a dialog/window containing a RadSignature-control and resizes the dialog (e.g. make it twice as large) then the position of the cursor on the canvas does not match the position of the strokes anymore. Painting in the top-left corner is sort of okay/close, but the further one moves the cursor towards the bottom-right, the bigger the offset will be.

The following JavaScript error is thrown when RadSignature is used along with asp:ScriptManager:

Sys.InvalidOperationException: '_uniqueId' is not a property or an existing field.