Can somebody please look at this pattern and tell me where I am screwing up?
I looked at the Paton's Cable Crew Neck pullover at Ravelry, that Jan linked us to. But sorry to say...we can't "look at" the pattern because it isn't an 'open pattern'. It seems to be in a book.
My advice is ROW ORGANIZATION and notes. Use stitch markers across the row, to mark the beginning and ending of important sections. At the end of each row worked, and before you turn the work, inspect each section to make sure you still have the stitch count right, and worked all the stitches correctly.
Keep track of the rows by installing thread markers somewhere after an important row, such as, if the row repeats are 12 rows tall, put a thread marker after each 12th row.
A complex cable pattern isn't hard, but you have to be organized and don't rush yourself. Go slow, go carefully. It's better to knit slowly and accurately (and in the end, it saves time because frogging and reknitting is a time-suck)
Here is a photo of how I keep track of rows with a complex cable pattern:
The black threads were keeping track of the 4 row cable repeats, and the [COLOR=Red]red threads[/COLOR] were keeping track of the 6 row cable repeats. By doing this, I always knew which row of each cable should be worked on each literal row. This also helps to create an exact mirror image for the Fronts or the Back, etc. You will know exactly how many repeats you worked to get to the armholes.
Do you follow what I'm trying to say? I'm an experienced cabled sweater knitter, but I still take the time to keep track of EVERYTHING on each row. It's a good habit.