Have you seen this problem yourself? I've been unable to duplicate it on either Linux or Windows XP, using free Acrobat Reader 8.1.1 dated August 20 on both platforms. I put all five ligatures in a latex file and compiled it directly to pdf with pdflatex, then as a double check indirectly with latex to dvi then to ps with dvips then to pdf with ps2pdf. On XP I did this with the latex that comes with Cygwin, on Linux with the latex that comes with Redhat FC4 (old system I haven't upgraded for a while). Is the problem independent of font? Of dvi-to-pdf converter? Of operating system? Etc, etc. Vaughan Michael Barr wrote:
Whatever you do, do not upgrade to Adobe reader 8. I found this on the texhax list.
Has anyone else been clobbered by the discovery that Adobe Acrobat 8 tacitly suppresses all ligature glyphs of the fi, fl, ff, ffi, and ffl sort and displays blanks in their place. They do this without warning, so that a file which displays perfectly well in Acrobat 7 is made unreadable in Acrobat 8.
It turns out that files converted (from the ps file) by the distiller (which costs something like $500) do not have this problem. I guess Adobe is tired of free use of their format. At TAC, we still consider the dvi to be the official format.
Michael