I posted this last week at ToyotaNation but could not get any good advice

I could use your input if you have a good idea what the problem is.

Yesterday, car started up and idled fine. I drove about 15 miles then shut if off for about an hour. It started up and idled nicely. I drove non-stop for about 275 miles. The usual MPG, Shut it off to get food. Difficult to start and very rough idle. No warning lights. I drove it home about 25 miles without any problems, ran strong as usual. I scanned it and found no regular codes but found a pending PO300 so I cleared it. Several hours later my wife said it idles rough and would not drive it. I checked the plugs, the middle two looked oiled. I looked down the spark plugs holes and saw the middle two piston tops covered in oil. I did a QUICK compression check: 1=160, 2=150, 3=145 and 4=155. I find it strange that the two middle cylinders might have suddenly lost spark intermittently??? Is this the beginning of a bad head gasket between 2 and 3? Temp was normal, good power, no oil in the coolant and no coolant in the oil. What should I check next??? Thank you.