Mark - I've run three different memory modules in my Rev 1.04 ASUS Refurb. All were installed as single modules. All are 512MB.
Crucial DDR 2100 at 166fsb (no problems)
LEI (Legacy) budget stuff DDR 2700 at 166fsb and mild overclock to 177fsb (died at 180 fsb in 3DMark2100)
Crucial DDR 2700 at 195 fsb (works great), can't get 200 fsb but I'm still on all the default voltages for CPU and Memory
No memory heatsinks on any modules.
Crucial DDR 2100 at 166fsb (no problems)
LEI (Legacy) budget stuff DDR 2700 at 166fsb and mild overclock to 177fsb (died at 180 fsb in 3DMark2100)
Crucial DDR 2700 at 195 fsb (works great), can't get 200 fsb but I'm still on all the default voltages for CPU and Memory
No memory heatsinks on any modules.