It sounds like your tree is too big to be on a single page in a PDF file. The topic is mentioned in the GEDitCOM II help as a footnote to printing trees:
"Note that you can save any size chart to a PDF file, but some other software may be limited in the sizes it can handle. For example, Adobe Acrobat and Reader are limited to 200 in X 200 in charts (16 ft 8 in X 16 ft 8 in)"
Thus, for example, if the printing service you use to print the tree is using Adobe Acrobat or Adobe Reader, the page size will be limited to 14400X14400 pixels and the two you mentioned were larger than that in at least on direction. Some suggestions are:
1. Check what software the printing service is using and/or find out the largest page they can print, regardless of what the software can do. For example if their largest printer is 8 ft by 8 ft, it won't matter if software can open something larger, because they could not print it all at once anyway. If then can printing something that large, try to see if they can use software that can handle large PDF. As I recall, I think the large PDFs open fine in Apple's Preview, even though Adobe Acrobat and Reader fail to open them correctly. One would think Adobe would be better since they invented PDF, but it seems not.
2. Once you know #1, you use GEDitCOM II to limit the trees to that size. Here there are two approaches:
a. Break the tree up to smaller pieces where each one is smaller than the maximum size your printing options can handle
b. In GEDitCOM II, "Print" the chart to PDF (using MacOS print to PDF methods) rather then "Export" to PDF. Before printing, you can use page setup to create a custom page size that is smaller than the largest possible printing at your printing service. The tree will come out on multiple pages in the PDF (if it is larger than that large page), but you can print those multiple pages at your printing service and then cut and paste to one huge sheet (if you really want something about 30 ft high).
3. Another option in GEDitCOM II is to make the chart smaller by customizing all the tree settings in the preferences window. By using smaller fonts, smaller cells, less space between cells, and les information in each cell, you can make it much smaller. It looks like you need about a factor of two smaller in height to fit the entier tree into contraints ot Adobe PDF software.
In summary, there is no limit to size of tree in GEDitCOM II and any tree can be printed to multiple pages on any printer. The only limits occur when you export to a single PDF file and then try to open that file in PDF software that is not as capable and cannot display large PDF files.
------------
John Nairn
http://www.geditcom.com
Genealogy Software for the Mac