Safari not smoothly displaying dynamic plot

I have a web-app that draws a graph by repeatedly drawing the plot in a Canvas…
For each new datapoint that comes in (through the internet, so not really regular) it redraws the plot.
For Firefox this results in a dynamic graph that really shows the graph growing with each new datapoint (say coming in at around 1 Herz). However Safari seems to cache and it looks like it only updates irregular. So now the user observes a very unsmooth grow of the plot. Sometimes it seems it buffers for at least 3 seconds.
Anyone has had the same experience? Can I do something at the coding side to get the graph displayed more smoothly?
Dick