I was going to suggest checking the adapter to be sure it isn't loose. It should be OK, maybe it wasn't tight enough when installed. Most of those kits use an O ring type seal. It's easy to find a replacement if you know the size, not sure if they all use the same type seal. I'm not a big fan of remote oil filter kits unless it has high quality fittings and hoses. If any part fails it will dump your oil and damage or destroy your engine. Look at this Perma Cool kit.
http://www.perma-cool.com/Catalog/Cat_page27.html
It has push on adapters that secuered by worm drive type hose clamps, probably the hose is low grade. I wouldn't install one of these kits on my vehicle.
If I were to install a remote kit I would get one that uses a common bigger filter. The Toyota filter is very small and adding extra hoses increases the distance the oil has to be pumped to get to the engine, a bigger filter would help.
My 2 cents,
Clifton