Plurks show new responses on some plurks when all existing responses have already been read.

Some plurks with responses that have already been read keep showing that they have new responses. This appears to be always happening with whatever plurk I posted last and some plurks from my friends. In the case of the plurks from my friends, I don't know if it is their last plurks or not because it hasn't happened consistently enough for me to pin anything down.

This doesn't appear to be connected to a refresh of the browser and seems to just happen normally as the timeline reloads new plurks and responses.