I just downloaded Picasa2 and created a bunch of collages.  I sent them
to Costco but when I went to pick them up they were useless.  The top
row of 4 pictures (16 total; 4x4) was cut in 1/2, and the bottom row
had been cropped as well.  the guy at Costco said digital cameras
require more space at top of each picture to allow for this
"autocropping," and that the effect is exaggerated as you enlarge the
prints (these were 8x10 sheets).

Is there a way to fix this using the current pics that i have?  Maybe I
could resize them somehow.  I really am new to all of this, so please
type slowly.  ;-)
Thanks!

I did search the topic on the Picasa support site, but didn't find this particular issue...

Many thanks!  

Copy to a memory card (or cd) and then on the in-store kiosk you can get a preview to see what is going on and crop/trim as necessary.

Part of the problem is the aspect ratio that Picasa uses to create collages.  There is nothing wrong with the collage system, it just does not work well for printing on photo paper.  I just created one in Picasa and it was 960 x 960 pixels or 3.2 x 3.2 inch.  ie. a square

The Costco printer probably defaults and makes one side fit the paper.  In your case it took the long side of the paper.  So if you take a square image and make it fit on the long side of a rectangle piece of paper roughly 1.5 inches hangs over on the short side.  Sadly the guy running the machine is not paid enough to spot this or even care.  There should be an option on the printer to make it fit in both directions.  Getting them to set that option will probably be a pain.  What you will end up with is an image that fits the paper with a lot of white space on the edges of one side.  Another downside is the total image will be smaller.

My recommendation is to find a printer that will work with you.  For the wierd print requests, I go to the local camera store and use their kiosk.  I even know the code to use the advanced editing features.  Being a repeat customer comes in handy.

Doc

Thanks for the input, guys.