Seemingly random plot area drift?

I've got a really frustrating issue with Excel charts. I am using Excel 2003
SP3 and XP.

I have a large workbook with many tabs. One of the tabs has about a dozen
bar charts. Every time I copy these charts into Word, and then go back to
Excel, the plot area has randomly moved. I don't do ANYTHING in this tab
except copy and paste those graphs. There is no shifting of column widths
etc.

Specifically, the plot area seems to shrink. I make a quarterly report with
these graphs and each quarter the plot area has shrunk until it gets so small
and scrunched into the middle of the graph that I have ot go back and
manually stretch the graphs out again. The problem is twofold:

1. Why does this random movement of the plot area happen? I'll not also that
the legend also seems to move.

2. My workaround of going back each quarter and manually stretching the plot
area back to fill the chart is also frustrating, time consuming, and
impossible to do perfectly the same in each of the 12 graphs because I'm
having to do it by eye. Why does Excel not have rulers and/or measured plot
area options? It seems you can only change sizes by eye. Therefore my report
looks unprofessional and messy because the graphs aren't all bang on the same.

Any help would be greatly appreciated!