I'm using version 126.96.36.199 and could see big improvements. One thing I've noticed is when a chart has single series and multiple categories the legend is set to show one series name on the chart in word 2007. After it's converted to PDF somehow the legend text is automatically replaced with multiple category names. It only happens with single series, I've checked a chart with multiple series and it looked fine after the conversion.
Please take a look at this issue and let me know when it's fixed.
Thank you very much.