David,
I understand the seriousness.
I guess you are working with our 4.2 version.
Previously we had these issues in Mozilla Browser and now many issues have been fixed.
So would you kindly install our latest version 4.3.X beta.
Here, this is the link to download.
http://www2.syncfusion.com/Installs/v4.3.0.22/syncfusionessentialstudiosetup.exe
Please let me you have any other queries.
Our Sales team will soon get you the Unlock Key.
Thanks for using Syncfusion products.
Thanks,
G.Pradeep.