Suspect that Portfolio 7 cannot handle more than 4.1 Gb catalog file size

I found the catalog process I ran on Portfolio 7 was stopped this afternoon. The error message said something like out of disk space. I checked the catalog file size and it said 4,193,312Kb. Rather than the problem causing by running out of harddisk space, I suspect that the real reason is that Portfolio 7 simply cannot handle file size bigger than 4Gb, much like the file size restriction on FAT32. Ironcially, both the Portfolio 7 app and the catalog files are running on a NTFS partition on a Windows XP box. Mystery indeed.