Lucille,
Unfortunately, veteran knitters can tell you that yes, sometimes you have to unravel rows (recently I had to take out an ENTIRE back panel of a cardigan, but that's another story). The key is to very carefully get all of the stitches back on the needle when you're done. Count to make sure you've gottent them all. Some of them may be facing the wrong way, so be careful on your next knit or purl row that you keep your stitches untwisted.
I recently learned a cool technique that could be of some help. A knitting instructor suggested threading a contrasting piece of yarn through the knitting (just slide it through the stitches on the needle) every few inches. Then if you have to rip out, it will stop the "ripping" and you can easily get the stitches back on the needle. I haven't had a chance to try it yet, but I think it's a great idea, particularly on a complicated pattern.
Hope this helps! Hang in there! <img src="/images/graemlins/smile.gif" alt="" />