Nah it's not the first, atleast he Nokia 5530 does the same... So probably all Symbian S60v5...

And the Li-Ion batteries don't have that issue or "memory effect" you mention, in fact you shouldn't even let it discharge all the way down.

I know Wikipedia isn't always 100%, but still check it out or do a bit of research on this

http://en.wikipedia.org/wiki/Lithium-ion_battery

Glad the N900 is "fixed" AtteK0 !