You're right. The wording is a little confusing in both cases. What I would suggest is substituting "level" for "pick" in the text. Thus you can increase any single professional skill by two levels per advancement, any non-professional skill by one level, your vaored reaction by two levels, and any nonfavored reaction by one level. There should be no limit to the number of skills you can increase except for the five picks each advancement provides.
So you should be able to improve, say, two professional skills by two levels each and one by one level. Or improve a nonprofessional skill and a non-favored reaction by one level each.
At least, that's my take on it.
As a side note, I'm sure the errata notation made sense to me when I added it, but now... Not so much. ::sheepish grin::
Former Decipher RPG Net Rep
"Doug, at the keyboard, his fingers bleeding" (with thanks to Moriarti)
In D&D3E, Abyssal is not the language of evil vacuum cleaners.