Ch'i

While I see your reasoning, Hektore, and thought along similar lines, there are a few symptoms boatin mentioned which pointed more towards undertraining. Though is certainly worth taking the time to clear up any ambiguity posed in the OP.

Diminished performance is usually the best indication that you're overdoing it. If you begin to add a few minutes to your usual time, or fail to equal or better the number of repititions per load, you're probably overtraining. I have four questions for you:

•Are you irritable?
•Have you lost your appetite?
•Are you having trouble sleeping?
•Are you experiencing any aching in your muscles and and joints?

If the answer is yes to any of these then a break is in order. Many top trainers recommend a week of total recovery every twelve weeks. This not only gives your muscles and connective tissue a much needed break but also gives your central nervous system a chance to rehabilitate. The central nervous system is put under a great deal of stress, so if it is not allowed time to adequetely recover your coordination may suffer and impede your strength.
I'm still in favor of my advice being premature. You're regiment seems balanced, so I'd stick with it. This soreness is not uncommon, especially in the chest and abdominals. In addition to stretching every day I would recommend, if you haven't been already, stretching before and after your workout. Go through the breathing exercise while doing so. You should also consider taking a very breif jog (2 min), juggling, or doing anything which would bring your heart-rate up before lifting.

If the soreness persists then it would be wise to seek out a fitness or training coach in your area. A trip to the doctor for a physical should also be in order, regardless.