Plural message gives error - in digikam.po

[Sveinn í Felli]

Hi,

There's one plural string in digikam.po (trunk) which yields an error; 
I'm wondering what would be the cause:

#: 
core/utilities/geolocation/geoiface/correlator/gpscorrelatorwidget.cpp:519
#, kde-format
msgid ""
"One image have been correlated. Please check the offset and gap 
settings if "
"you think that more images should have been correlated."
msgid_plural ""
"%1 out of %2 images have been correlated. Please check the offset and gap "
"settings if you think that more images should have been correlated."
msgstr[0] ""
"Ein mynd hefur verið pöruð við staðsetningarhnit. Gakktu úr skugga "
"um að stillingar á tímabelti og frávikum séu réttar ef þú heldur að 
fleiri "
"myndir hefðu átt að vera paraðar."
msgstr[1] ""
"%1 af %2 myndum hafa verið paraðar við staðsetningarhnit. Gakktu úr 
skugga "
"um að stillingar á tímabelti og frávikum séu réttar ef þú heldur að 
fleiri "
"myndir hefðu átt að vera paraðar."

Both SVN and msgfmt give an error for this message:

$ msgfmt -vc digikam.po
digikam.po:48960: a format specification for arguments 1 and 2 doesn't 
exist in 'msgstr[0]', only one argument may be ignored
msgfmt: found 1 fatal error
9059 translated messages, 2 untranslated messages.

I guess this must be violating some gettext-rule about that if there are 
2 variables in a plural form, there must be at least 1 in the singular 
form. Right?

At least the French have translated this by adding '%1' instead of their 
translation of 'One'=> "%1 image a été corrélée" which passes the tests.

Is there any other way of doing this?
Perhaps this should be modified in the source string?

Best regards,
Sveinn í Felli