Got some ram over Christmas, ddr400 2x256mb for my 18Ghz (single rev a) Powermac G5. Only got back to my puter in london to install it yesterdayday. It went fine and everything seemed fine until yesterday evening. Symptoms iTunes crashed numerous times when just trying to rename song tags or import songs, when i re-opened it my library had been lost or the library file corrupted. Safari unexpectedly quit and again when i re-opened it it had lost its pref's. It was like it had been reset. If it weren't for my powerbook i would have lost all my bookmarks. Azureus quit in the middle of a download, much to my annoyance. Illustrator told me that it didn't have enough memory to open the file...(a blank page) And photoshop crashed on opening. So to recap i had multiple kernal panics and it pissed me off no end, i was just hoping it wasn't the ram. Now i did install the 10.3.7 update yesterday too but i have just taken out the RAM and now everything is back to being super stable. Just one thing to note, when i installed the ram the g5 wouldn't boot with it in slots 2 and 3. I had to swop over the original ram in order to get it to even boot. i thought it was weird but maybe just a quirk? i'd never installed ram in a mac before, just my pc. I thought maybe it was being fussy. I searched the threads and found some similar probs but just wanted someone to confirm my suspisions. So my question is has anyone else bought RAM from crucial and had it utterly piss around with your mac? will they just swop it? i should have known it was bad when it wouldn't work in the slots the first time i tried right? I drew a quick diagram incase i was being to cryptic, showing the combinations i tried when installing the RAM.