The file http://math.gmu.edu/~sap/diffeq/L01X.xht has a number of embedded CDFs which load correctly using Chrome in Windows. Yet the CDFs do not load in Firefox. On the other hand when I view the file when residing in my desktop computer, the embedded CDFs display correctly in Chrome, FF, and even IE. Is this a matter of server configuration or issues with FF?
Just a data point:
The CDFs at your link seem to work fine in Firefox on OSX (aswell as Safari and Chrome)
It works fine also in my desktop PC (Firefox 25.0.1 + Windows 8.1). Anyway it seems that some of the links (i.e. to other lecture notes) don’t work.
Btw: very nice lecture note. Are the CDFs available (somewhere) for examining them in Mathematica?