Wow, you had different experiences then me. My 1.8A is in an ASUS P4S533 @ 2609MHz (145 x 18) with default voltage of 1.5. PCProbe shows 1.51-1.54, drops to 1.49 under heavy load, always rock solid stable, zero crashes in over two months.
Got a 300W PSU, no idea what brand, doesn't say on it, but it came with my case. Case is from some brand "Sabadda" (spelling might be wrong) that i'd never heard of, i bought it because it was fairly cheap, had a nice window and was sturdy.