well, it's possible those devices don't exist! the "partitions" exist, but linux doesn't know how to access them because only a limited number of harddrive devices are created. here's a quote I found on the web that relates - hope it makes sense:
...to save time (or disk space) and RAM, we don't
create device nodes for those partitions. It is extremely unusual
for users to have more than 8 partitions on a non-primary disk.
You can get the device nodes via
mknod -m 600 /dev/hdb9 b 3 73
mknod -m 600 /dev/hdb10 b 3 74
mknod -m 600 /dev/hdb11 b 3 75
note, this relates to a non-debian distribution, but it's likely you are experiencing the same issue. few people even have a /dev/hda14, so it seems possible that the debian folks don't create any devices that high. but, like the above quote illustrates, you can just make your own!
will give you some more clues. also, your major and minor numbers will be different than those above. try to figure out those numbers for /dev/hda13, and start numbering sequentially from there.
anyoo, hope this makes sense, and helps! good luck!