"Fraser" wrote in message ...
Hi,

snip

there is a polycell plaster repair filler which is pretty good at
covering problems...

I always paint the walls with a cheap white paint, this shows up the
problems, fill all the bits, then paint it again with the cheap stuff
just to make sure its ok, then paint it for real...

I would suggest just filling the really bad ones, sanding the wall by
hand (i found it quicker than an orbital sander? and you get a flater
finish because your not just sanding little areas at a time) just to
remove any lumps, then use lining paper.... then paint..