Sometimes, I cannot add new words into Skritter. It happens in this scenario:
I have a list, where I edit a section and want to add a new word; so I enter the pinyin (without tones). If there are already words existing with the same pinyin, I only can choose one of the displayed items, however, if my word is not in the list of displayed items, I cannot add a new one. Only if this pinyin doesn't exist, I have the chance to add a new item to skritter.
If I enter pinyin with tones (=numbers behind the syllable), Skritter doesn't recognize this at all.

I don't really understand why this would be a problem. Why not just add the words by writing them in characters?

i don't understand either

That is the way to get around this. You're going to need to write the characters anyway in order to add them as the word.

The list editor should be able to handle pinyin with tones though. Could you give an example of something it doesn't recognize?

OK, thanks, I'll use characters instead.

Scott, this happens, when Skritter doesn't know this specific pinyin, it just shows "search again", so I will use characters.

I think we did it that we on purpose to minimize crazy submissions, since most of the time when people were creating words after just inputting pinyin, they didn't know the right characters.