It's something on your end, I would gather. It could be a variety of things. From the version of the Windows you are using (since saves are written to the Windows Registry - though, it SHOULDN'T matter) to a bad install (good news is, you could delete, download again, and extract again - the saves in slot 1-4 should ....
WAIT. What do you mean by "1-4 slot"? There are 18 pages of 9 slots per page. Do you mean pages 1-4 and 5-18?? And there is no reason you should need anywhere near 36 saves for this update.