Please R0J0hound, here some more detail from my observations... maybe you could find some time to take a look... ?!
Simple Project: just the Canvas Plug-In and a simple procedure to draw a line with every mouse movement.
Link to HTML5 uploaded: HTML5 Site
Link to C2 r132 CAPX: CAPX
You can try this at home: start moving the mouse over the Canvas Object and observe the memory amount needed for the browser application. I took two screenshots, one from Chrome (version 27.0.1453) operation and one from Mozilla (version 21.0). Both behave the same: crashing after memory full.
Links to both screenshots: Screenshot 1 Scrrenshot 2