Disk Utility Partitioning Issue

I bought a new 2TB portable external hard drive and I wanted to set it up so there would be two partitions - 500GB for time machine backups and 1.5TB for miscellaneous other stuff that I don't want on my main SSD. I partitioned it yesterday and typed in 500GB for the new partition's size and it formatted it to 506.00 GB instead and left 1.49TB for the other partition. I decided tonight that I'd resize the time machine partition to an even 500GB but now I'm not able to resize the other partition to 1.5TB -- it won't let me go any higher than 1.49TB.

Is there something I'm missing or did I screw something up? I've already moved hundreds of GB of data to the larger partition and I really don't feel like having to start everything over so I'm hoping there's a simple answer to how I can increase the partition size.

Any help would be appreciated

Here's a picture of the tiny bit of space between the partitions that disk utility won't let me do anything with if that helps at all?

inscrewtable said:

1000 bytes equal 1 kilobyte but drives have 1024 bytes in what is known as a kilobyte. Something like that anyway, don't worry about it.

Click to expand...

It's actually 6.02 GB that I've lost which in comparison to 2 TB is nothing but I still don't want it wasted, that's like 6 HD movies...