A quick note: I’ve just upgraded to the latest version of WordPress (2.6) mainly because I keep getting this little note in the admin area telling me I need to upgrade… it’s niggling. And I don’t like to be niggled all the time.
On the other hand, if you find anything broken or troublesome, please drop me a line and… how shall I put it? Niggle me, please. I’ll fix it. Eventually.
According to Collins Essential English Dictionary (via thefreedictionary.com) the verb to niggle means either to worry slightly or to find fault continually. As a noun, it is a small worry or doubt or a trivial objection or complaint.
You may also wish to fuss, nag, carp, criticize, cavil or nitpick but, if I were you, I would stick with niggling… it’s more polite. Although quibbling is also acceptable. You might also consider pettifogging.