Got gauge?

Yay, K is coming back today! I'm not only saying this because he brings back the camera and then I can take pictures of the swatches I made with the new yarn I just bought... which brings me to gauge. I've noticed this before when I made gauge swatches, that I get the number of stitches right, but not always the number of rows. I then usually figure that if I adjust the needle size to get the row number right, then the stitch number will be messed up. I regard the stitch number as more important, as I need to count the stitches (when casting on, increasing, decreasing, etc.), but the length of what I knit is measured in centimeters, not counted in rows. Or do I get something wrong here? How do you handle this?
Even if I had to have the row number correct, how could I do this without affecting the stitch number? Knit tighter/looser, but not wider? Is that even possible? What are knitters like me supposed to do when this happens, or is this just "knitter's bad luck"? Books etc. only talk about the amount of stitches, and how to adjust it. But I never read anything about the importance of row numbers, or maybe I only overlooked it.

Edit: I just checked my Knitter's Almanac (aka Elizabeth Zimmermann's (or is it Montse Stanley's?) Knitter's Handbook), and it says that the stitch number is more important: "When trying to achieve tensions stated in instructions, it may be impossible to achieve botch stitch and row counts. Concentrate on the stitches and, if the row difference is large, avoid projects where the numbers of rows are crucial. In projects where length is checked with a tape measure rather than by counting rows, remember that you will probably need a different amount of yarn than the instructions say."
I think I should read my knitting books more closely. Problem solved!