So there is a 20KB limit.
My Avatar is 20KB.
I can't upload it... WHY?
That's because:
1 KB is 1024 B
I thought 1KB is 1000 B !!!! <= that's because people like numbers whit many 0-s (especially when they talk about money)
The fact is that when we talk about very limited space... every byte counts.
The actual limit is 20000 bytes not 20 KBytes (20 KBytes = 20480 Bytes)