from what's bewen said it seems like the canvas has some performance issues. I have quite a bit of background in relation to tuning rendering engines for performance. help i used to do 3d animated graphics on a 386 with a few mewg of ram. even sqeuuzed a simple cad package onto as bbc computer with 32k of memory.

basically, if i get time i'll take a look at it and tyry to identify what the performance bottle knecks are and how to improve them.