The walls around the windows in my bedroom are getting mould growing on them. It appears to be just the areas of 'dotndab' that are effected. Any advice on overcoming this issue?

Is the wall solid construction, ie no cavity. What type of plaster was on there previous to d&d. Did you have damp before the d&d was done.

Sounds like you have water ingress around the frames and the bonding compound is sucking in the moisture......

It sounds like the dotndab plasterboard has been applied with bonding coat plaster onto the wall which is drawing the moisture in from outside. If the wall is not a cavity wall, I would suggest that the plasterboard is removed, chop off the rendering back to the brickwork on the area affected and rerender in sand and cement with a waterproofer and reskim. If it is a cavity wall, there should be a damp proof membrane in between the cavity around the windows which will need to checked. If it is not present or has perished, the moisture will be able to get through. Hope that helps. Best wishes, Chris Robinson.