Painting - How to clean up paint mess

I have purchased a condo that I am having the kitchen redone. I have discovered that the previous owners used an oil based paint over latex and it peels up like a bad sunburn. Problem is, it doesn't peel in all places and is stuck like glue in those areas. Sanding does not seem to take the paint off. What can I do to smooth the wall out for painting with a water based latex paint? Many thanks for any help -- this one has me befuddled because I thought light sanding would take the paint off. Patti

I think you mean they painted latex over oil which would be why its peeling up. Scrape off everything you can, prime it with an oil-based primer and then smooth out the uneven areas with joint compound. Prime the patched areas again, either with the original oil primer, or with a latex primer, then you can apply a latex finish coat.

Thank you for the quick reply -- tomorrow is the big day I start this project!! Patti