So I was just partitioning my hard disk to get it ready for installation of multiple Linux distributions and that's where it happened. I booted up my notebook using an Ubuntu 10.04 Lucid Live CD and used GParted to partition my hard disk.
First, I created an extended partition that would cover my whole hard disk (don't worry, I backed-up everything twice and stored it on my server). Then, I decided to skip the first GiB of my hard disk and started creating multiple ext4 partitions (10 GiB each) and labelled them so I'll be able to tell which partition contains which distribution later on. When I was satisfied with the result, I created multiple 100 MiB ext4 partitions at the very beginning of my hard disk (the first GiB of unallocated space, remember?) which I'm planning to mount as boot partitions for each distribution. But, when I successfully created 16 logical partitions in total, GParted refused to create a 17th partition, let alone an 18th and so on...
Now my question is: is GParted unable to create more than 16 partitions on a single hard disk, or is it a known fact that an extended partition cannot contain more than 16 partitions (so that it would be wrong to blame GParted for this). So, is it possible for me to create more than 16 partitions using a work-around or manually partition my hard disk using the terminal, or should I not create as much partitions on my hard disk?