thanks for the report, we've just introduced a new bug template that will help us migrate bugs from the forums to our bug tracker. Could you please update your ticket to follow this template so that we can address it faster?
I reported something similar a while back. My IE8 on Vista basically choked on anything involving the new vml stuff, including charts and vertical text. IE8 on some other platforms worked. Different versions of IE seemed to work. However, IE8 on vista always bombed out for me. Sencha said they couldn't reproduce it, though, so I ended up thinking it was just something wrong with my install. Glad at least someone else ran into it so I know I'm not totally crazy
From where that occurred, it looks like it wasn't able to create the surface. We'll add an additional check to ensure we have one before adding listeners. But you still may not get a chart. I'll see what we can to to get that exact combination of OS and browser. But the 32bit vs. 64bit we also need to know.
One other item to look at is the "Binary and script behaviors" setting in the Internet Zone. It must be set to enable in order to render VML in the Browser. This may be the root cause of your problem with displaying the VML charts in the first place, but I have also added the surface check so you will not get a hard error in the future.
I can't speak for the OP, but I have the similar problem and I'm running IE8 on Vista 32-bit.