So I got a 1.83ghz MacBook a month ago (whines, moos, don't really care). Being a bit of a skimpy idiot, I installed a dirt cheap 1GB DIMM a week later (can't remember what brand it turned out to be), and then a second cheap gigabyte a week after that (the chips are marked 'GeoTech'; never heard of them). Both sticks are rated CL-5. A couple of days later, the machine hung (not even a kernel panic curtain, just insta-freeze). I wasn't doing anything myself with the machine at the time, I just sat back down at it and it wasn't responding. This was worrying, but a further two weeks of blissfully smooth operation and I put it down to a random glitch. Alas, it's just hung again today... bunch of programs open, dragging things around in iTunes... the audio started to repeat like a scratched CD. System.log has nothin'; just the subsequent boot logs. I guess the most likely explanation is the cheapskate RAM... Techtool Pro universal beta reports no problem, but I'm told that minor memory glitches may only show up under certain conditions. I've found a lovely shop that sells Corsair memory for less than what I paid for this stuff, so if I can get refunds, I may go for that. Or I could get Kingston memory for a little more again. Not too sure of my chances on the refunds though. Questions: How likely is it that one (or both) of the sticks is indeed faulty? Would it be worth spending another $A310 on somewhat higher-class memory in any case, or perhaps replacing one stick and then the other to see if just one is at fault? Is there a better explanation for the hangs than bad memory? Which brand is worth going for? Am I completely overreacting? I'm pretty sure the only things that were plugged into the machine both times were the power cable and a USB mouse; and from memory I had nothing much in the way of software running the first time - I think 10.4.7 on both occasions. This is my first Mac since spending six years with a PC after growing up with Macs, and I'm a bit out of touch. Just trying to avoid wasting time and money on fruitless exercises... Thanks in advance. I'll try the shops for refundings today.