strange lyric problem

[James E. Bailey]

I've just got an error on something that I've used before and after  
(in the same file!) and I don't understand it
GNU LilyPond 2.11.49
»Scene_1.2.ly« wird verarbeitet
Analysieren...
Scene_1.2.ly:170:35: Fehler: keine gültige Dauer: 47
        mei4. -- de!8 \skip4    |
                                   %47
Scene_1.2.ly:173:27: Fehler: keine gültige Dauer: 56
        nah’?4. \skip4. |
                            %56
I use bar checks and measure number checks in every measure, and for  
the first time in lyricmode, it's processing the % as a word.
 the lyrics section of the manual doesn't mention anything about %
A word in Lyrics mode begins with: an alphabetic character,  
_, ?, !, :, ', the control characters ^A through ^F, ^Q through ^W,  
^Y, ^^, any 8-bit character with ASCII code over 127, or a two- 
character combination of a backslash followed by one of `, ', ", or ^.
and the same file doesn't have errors for measure %1 through %46, %48  
through %55 and %57 to the end in any of the 6 other parts I've done  
so far.

Of course I can just leave out the checks for these two measures, but  
oddly, the % shows up as a word in the score.

Should I just ignore it, or will this cause problems later on?