What should I be looking for to fix the normals after adding a surface modifier and it appears wrong?

Laptop Studio XPS Intel Duo Core CPU 2.13GHz 4GB RAM, Win7 64-bit, ATI Mobility Radeon HD 3670

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Where Splines cross or meet, there must be a vertex on both splines - those vertices must be coincident (occupying the the same location in 3D space). Fuse any which look as though they may have become separated.

If you consider the splines to be “edges” then the enclosed areas between them are “polys”. Those “polys” can only have 3 or 4 sides (edges). Any more than that and you will get holes in the surface.

Finally, check the tangents of the vertices - it is possible to get them rotated such that they look correct at a quick glance, but they can cause tiny “loops” on the splines of which they are part. You will need to “unwind” any that you can find.

If all else fails, zip the scene and post it so we can take a look.

Max 4.2 through 2013.
XP-64 (SP2)
NVidia 9800GTX-512 (Driver 266.58).
Core 2 Quad Q6600 2.4GHz, 8Gb Ram, DX9.0c.