In plain TeX, \ddot{a} places the double-dot accent correctly above the letter a. However, if I (attempt to) switch from the default (Computer Modern) fonts to ec-lmr10 (I believe that this is Latin Modern?), the double dot accent ends up in the middle of a.
Running pdftex on the code below gives me two correct "double-dotted a", two correct "vectored a", then two wrong "double-dotted a" and two correct "vectored a", so the problem depends on the accent.
$\ddot{a}\mathaccent"707F{a}$
$\vec{a} \mathaccent"017E{a}$
\font\tenrm = ec-lmr10 at 10pt\relax
\textfont0 = \tenrm
$\ddot{a}\mathaccent"707F{a}$
$\vec{a} \mathaccent"017E{a}$
\bye
Two questions: What is causing the diffference? (Some fontdimen parameter, perhaps?) And what am I doing wrong, how could I fix that?
