Vantage 4.812 performance

Fellow Epicorians,

we've just migrated to V4.812. Everything is running OK, but
response's have gone
south. Our sever (Compaq 3000, dual 550's, 1G RAM) was adequate in V3.
I just received
a complaint in a user running the Time Phased Material Report. It took
5 minutes in V3,
and 15 minutes in V4. Initial program load also takes longer.

My question is, is there anything that can be done to improve
response times.
Creating the schema file does little to imrpove performance.
TIA.