Richard:
If anything was affected, I suspect it was the Liquin. That is certainly the cheapest thing to replace and see if it fixes the problem.
Normal oil paints can be put into a freezer and will be unaffected - they are pigment ground in a natural drying oil like linseed or safflower or walnut. I wonder about alkyd paints, however, as I believe that they are pigments ground into a synthetic petroleum-based oil and an alkyd resin binder.
Try the least expensive fix first.
