At some point along the line, the IE9 gradient rules have been removed?
filter: progid:DXImageTransform.Microsoft.gradient(startColorStr='#F2FFBD', EndColorStr='#BCEC00');
This caught me unawares with a client! It's a very useful bit of code and I don't think it should have been removed, although I worry it was done deliberately?
Paul removed it back in November because it causes performance issues. Check out, c9f7876#L0L100