Help (again!)

Took the oil filler cap off today and found excess oil of normal black colour sitting in the oil filler cap area (between oil filler and black o-ring). I was suprised it had escaped?

Also under the filler cap was a greyish white sludge/slime. Checking the oil dipstick there was no more gunk but the level of the oil was indicating just over the max fill level mark.

Could I have a head gasket problem or is it more likely that the sludge is from condensation and due to short journeys over the last few days? Also why would there be excessive oil just sat in the oil filler area?

I had a change of oil a couple of weeks ago, could this count?

Aaaaarrrrrggghhhhhh, one thing after the other at the mo. Still trying to figure out why my temp gauge drops to zero everytime I go round a left bend or stop.

Please help.

Jules