I recently bought an Acer Aspire 5741G laptop, which has an Intel Core i3 330M processor inside. This processor has an integrated dual channel DDR3 memory controller which only supports 800 MHz and 1066 MHz DDR3 memories.
The DDR3 memory modules mounted in the laptop have IC's on it with part number K4B1G0846F HCH9. These are DDR3 SDRAM's of 1333 MHz, which are incompatible with the laptop's processor. The correct DDR3 SDRAM IC's are K4B1G0846F HCF8.
I'll start bothering the Acer support for new memory modules now, probably an exhausting task...
So just a heads up: if you experience problems with this laptop (which might disappear when the laptop heats up a little), be sure to check the datasheet of the mounted DDR3 SDRAM IC's.