Another peeing problem...

I found this forum because I'm pretty desperate. Our 3yr old female cat has recently starting peeing on things again. History is-
Bought from pet shop at 8 weeks. Had problems with peeing on things.
Got over it. Didn't pee on things.
Started peeing on things again. Specifically me when asleep. I would wake up because she was clawing my leg to try and cover it over. Banned from bed. Pretty well didn't try and get on bed as she would be kicked off straight away.
Behaved for ages, until we got some bean bag beds for the dogs. She slept on them a few times then decided to pee on one. Sounds like litter perhaps? Bloody annoying.
Behaved. We moved. Behaved. Put a mattress down for animals to sleep on in the lounge room. Slept on it for a few nights then peed on it. Mattress moved outside with all other peed on items.
Last straw. Peed on very expensive new lounge. Moved cushion to clean it. Banned from lounge. Peed on the spot where the cushion is missing! Fiance put bicarb soda on to soak up smell. Peed on bicarb soda on spot (this would have been the space of 10 mins). Fiance is sick of it (she's his cat too) and she is facing a life of sleeping in the bathroom if we can't change her behaviour (or worse).

Some more background. There is no real pattern to when she does it. Sometimes she does it when the littertray is completely clean, others when it is dirty (understand if it's dirty, but not when it's clean). Tried out a new type of litter for a while, but reverted to the old type because the other type is really expensive. She does not obsess over my fiance, and is as friendly with me as with him. She gets on well with all other animals in the house. She is spayed (and has been since 6 months). The littertray is very big and the cats are allowed outside durng the day. I can't think of anything else. Do you think maybe she liked the new litter and is protesting about that? It just makes no sense, she goes for months with no problem then suddenly she starts doing it again...