The problem in which codestyling localization does not save plural translations into the po file still exists.
(see Brozman's problem here: http://wordpress.org/support/topic/plugin-codestyling-localization-plural-form-in-header-of-po-language-file-bug)
Author of plugin said in that thread that the problem will be fixed in version 1.99.25, but I have ver. 1.99.3 and it is happening to me.
BTW, thanks for this great plugin.