Thank you Rouge, yes, disheartened was one way of describing it! From memory, it was something about the fudgey consistency, and falling apart too.

And Tan, I will endeavour to give the microwave ones a whirl too.

Lastly, just to confirm, for a brownie noob like me, do I let them (both conventional and microwave versions) cool completely in the pans? If not, how do you stop it disintergrating when you try and take it out of the pan?