First off, my impressions, are:

1) If you eat alot of RED beans...these are difficult for some people to process. Cut out the red beans, and substitute black ones (easier to tolerate) and see if that helps. It has to due with lectins on the red beans.
http://en.wikipedia.org/wiki/Lectin

2) Numbness at night is often due to low blood sugars.
Have a snack before bed, like a Zone Perfect Bar...etc.

3) Tests for magnesium in the blood do not always reflect "normal" in that middle range. They are most useful for very very low or very very high levels..which are medically screened for. That middle range does not reflect intracellular magnesium, which is where it is supposed to be. Imbalances with calcium, where calcium is consumed in large amounts, and magnesium is not balanced with it, can cause paresthesias. Typically there is alot of magnesium in beans, however, but your calcium then could be too low (not enough Vit D? ) and that also causes paresthesias.

Calcium you consume is not all absorbed you know. There are membrane limits in the GI tract.
This is a long paper on calcium in general. It states that most calcium is only 30% or so absorbed. I learned that it was more like 20%.. If a person is very low in Vit D... the level of calcium absorbed becomes lower.
http://www.jacn.org/content/19/suppl_2/119S.full

I'd get tested for Vit D levels. Often very low D leads to paresthesias.

I believe the Zone program is the most sensible way to control diet. So I'd keep on with it.

You really should get a B12 level done as well, when you get your D tested. Low B12 is common these days, and causes lots of nerve issues. Don't accept "normal" from your doctor. Get the numbers. In US now the lowest normal is 400pg/ml. If you are below this level, you should supplement. Use Methylcobalamin which is the active form of B12 and very inexpensive. Mostly has to be purchased online from any quality place, like Puritan's Pride, iherb.com etc. Pennies a day. Also must be taken on an empty stomach. Depending on your test results, that would point to a dose. 1000mcg a day for minor lows, and 5000mcg a day for serious lows. Labs in US still report levels below 400 as "normal"...and doctors don't know this, and tell the patient, normal, and you will then go on to have chronic nerve damage day by day!

4) some people are intolerant of Nightshade veggies... potatoes, tomatoes, PEPPERS, and these when consumed in large amounts like people tend to season vegetarian meals, can really cause paresthesias and burning sensations. Avoid these for a while and see if you feel better as well.

Come to our Peripheral Neuropathy forum here for more information and discussions:
http://neurotalk.psychcentral.com/forum20.html