8BA Front Seal Oil Leak

[Pete from OZ]

Hi Fellas,
I need advice on the Front Oil Seal . When I rebuild the 8BA engine I used the Modern front seal and not the Rope Seal. On first start up, I noticed a oil leak running down the centre of the oil pan from the front.
After reading a lot of posts , I thought maybe I pinched the seal. Sure enough that is what I did.
I have just this last weekend fitted a new speedi sleeve and new modern seal from Flatattack racing.
I made sure I did not pinch it by using insulation tape from side to side before install. This made it very easy to fit. I was very confident.
I ran the engine to operating temperature and shut down, and saw no leaks.
About 10 minutes later I checked again, and sure enough there was a leak again running down the centre of the pan from the front seal area.
What do you reckon I have done as I am certain that I have not pinched the seal.
Is this a common leak in this area. I also have not over filled the oil level.
Thanks.
Pete from OZ