A.,
Every child is different. We all know that, especially if we have more than one child. It does sound like he's teething again. One thing that has worked well for both my kids was to give them a dose of the Infant Tylenol right before bed, and only as they really seemed to need it throughout the day.
My son got his first two teeth when he was 4 months old, and then nothing for 7 months. His always sprouted in pairs fairly easily. He's now 4 1/2. My daughter turned 1 last month and got her first tooth a couple of weeks before her birthday. Hers are not nearly as easy as her brother's. Her second tooth is starting to make its appearance and if it's anything like her first tooth it will play hide and seek for several weeks before it actually sprouts through and stays.
Give him some extra love and cuddles, and try to keep your sanity/patience.
Hope this helps,
Melissa