Something strange is happening with IE9 and transform lists for SVG. This mini all-in-one doc tries to illustrate it.
Under chrome or similar, the box below with text should change size and move about a bit with each click of the button - there are 2 transforms and they're each adjusted on each click.
Under IE9 beta the box moves on the first click, and then stays the same size. The underlying transformation matrices do seem to get modified correctly, but the display doesn't change after the first modification.
Now if you try to debug it, it gets slightly weirder - and I don't know if this is just because the developer tools are in beta, or if the true problem is actually something to do with the optimisation of the javascript in their new engine. Certainly breakpoints seem strange (spread across multiple lines etc) and it seems as if the matrices actually get the new value BEFORE the transofrmations are modified - this could be just a symptom of the debugger struggling with optimised and re-ordered code, or it could be a bug with the optimiser that it's actually applying the changes at the wrong time (altho I expect not). If this was C++ code or simialr I'd drop into the assembly code view and see what's really happening, but as it stands... well... maybe someone from the IE team can take a look and tell me if it's just somethign as dumb as me mis-using the API (but I expect not).
Internal code is a bit convoluted as it's stripped down from a larger example (so hides state in window members and the text of the doc), and has been hacked around to see if logging messages etc shows any changes, but it should be pretty obvious what it's doing.