choc:: if you dont use fleece ( which i understand, its getting too hot anyways for it , and yes it leaks .. ) what do you use for liners ??
Just trying to clarify if you have used a fleece cover? As the fleece breathes it can feel damp to the touch on the outside as it lets the water evaporate.
The fleece for covers is different to the fleece for liners.

I'd try re-lanolising he longies and give them another go too. use them during the day to test their effectiveness before trying them at night again.