PNG exporting is not consistent across PCs (previously was)

Hi, we are using Oxyplot for unit testing where we compare the PNG image exported by the test with a verified baseline. This was working until recently - all of a sudden there are failures due to micro changes in the text rendered in the graph. 

Baseline

Generated by test

The text which is generated is not consistent across PCs, we are getting different failures. Can you please suggest how we can again start to get consistent exporting in PNGs?

Oxyplot version: 2013.1.52.1

Thanks,

Rishikesh