[bug?] eps versus pdf problem?

[Juergen Reuter]

Hi,

the white mensural ligature example lily-2147380820.ly in Sect. 7.7.10.1 
collapses in the HTML manual to a width of a few pixels (see the _first_ 
(almost invisible) png image in
http://lilypond.org/doc/v2.9/Documentation/user/lilypond/White-mensural-ligatures.html).

However, in the PDF manual, the same example shows up perfectly.

Hence, I guess this behaviour is probably an eps versus pdf problem rather 
than a problem of the ligature implementation, right?

Greetings,
Juergen

P.S.: I can eliminate the symptom in the manual by slightly modifying the 
example, but I guess finding the bug would be more satisfactory... ;-)