I have a relatively large music collection and run amarok 1.4.10 using the mysql backend on kde 3.5.9.
When i open amarok, its memory usage listed in top (RES entry) is about 30-40MB, which is normal. I can use the collection browser tab, context tab, and file browser tab fine and play music, without the memory usage going above about 60MB, which is normal and ok.
If I switch to the playlist tab on the left, amarok freezes as it loads for about 5 seconds, then functions as normal, and the memory usage jumps straight up to about 200-250MB, which i think is ridiculous.
Is there a reason for this that is known? Or is it possibly a bug?
Thanks in advance anyone.

I've never heard of such a bug such as you described.

At any rate, Amarok 1.x is no longer actively maintained, as we are focused on the latest stable release, which is Amarok 2.x.