On Friday we released new builds of all our WinForms / ASP.NET products. The big updates were some enhancements to the renderer management framework that is used primarily in UIStudio and SyntaxEditor. All the controls in these products would attach to an event on the renderer they used (typically a default global renderer) that told them if a renderer property was modified. This way the control instances would know when to redraw themselves. The problem was that sometimes even after a control was done being used, unless you called Dispose on the control (which forced removal of the event tie), the control may still be retained in memory due to this event tie.
What we did in this new build is update our renderers to support a weak event pattern. All the controls now use that pattern, meaning that the event tie will no longer keep the controls in memory, thus helping prevent against any possible memory leak scenarios.