Hi again, please don't lock me out of my own thread as the issue was not resolved.
With regards to my problem of 1 site working and 1 not, PHP is fully supported on the new server, it's professional-grade hosting with all the bells and whistles (on Linux), and in fact both sites are on the same machine. But as my previous post indicated, when you visit any of the PHP pages such as [external links are visible to admins only], a blank screen comes up and the app doesn't function. It worked a month or two ago when I initially set it up.
Any further ideas as to the nature of the problem? What could I do to fix this?