As of 1.2.0.3, an unmodified ditto does not properly copy the previous pitch if + and - were used in combination; it effectively ignores the - portion unless you only used -.
^s +-n1 * . +2-* * . -5* *
The above results in the notes playing at 105%, 110% (when it should be 105% again), 115%, 120% (when it should be 115% again), 75%, 75% (correct).
Also, less important, but "+2-3n1" (combining + and - with a number after the -) doesn't work, though I'm not sure whether it ever did. "+2---n1" does work, however.