About the memory issue when playing big map with a lot of AIs, planes, moving columns of tanks/trucks and static objects:
Try this
http://www.sas1946.com/main/index.php?topic=16403.0
I use it since the 2.3.0 version on stock Dedicated Server and Client.
My old rig
µP: Athlon 64x2 2.2 GHz
RAM: 2 GB DDR2
OS: XP Home SP3
I run both every day online 4.13RC04m DS + Client + TS3 Server + Client + TrackIR + Stats.
If you don't use IL2 Selector you can't join. The stocks version don't allow enough memory for heavy missions...
It's an old problem...