Actual physical memory can cause this at times. Usually in the form of a bad stick of RAM or just a section of the memory that had something stuck in it and it can't free it up. When the application (in this case Sketch Up) is trying to write to the same spot each time, it crashes.
There are a couple of things that you can try, one of course is getting a RAM testing application and run that.
Other options include shutting down the computer all the way, unplug it and then unplug the RAM for at least 10 minutes. Then replacing the RAM and plug everything back in and try it again. What this will (should) do is allow any residual electrical charge that being stored in the circuits to be completely removed. If there is something stuck in RAM, this should free it up. If you still experience the issue after this test, then run the RAM checker program if you already haven't.
Another thing to check is what is your Virtual Memory (Swap) size?
- To do this, Right click on the "My Computer icon and choose "Properties" option.
- Click the "Advanced" tab
- Click on <Settings> in the Performance section.
- Click on the Advanced tab
Note the current size settings under the Virtual Memory section
Click on the <Change> button and note how VM is handled, Is it set to a specific size, is it system handled, ect. and let us know.
I always suggest setting it to system managed This is to ensure that you will have enough swap space. The downfall of this is that it will use up more disk space than what you would like it to. Plus if you're hard drive is pretty full (you have less than 5GB free) it can cause issues. Microsoft says it will never use more than the amount of physical RAM you have but they LIE.
I've seen the swap file grow to 5gb in size on a machine with only 1 GB of RAM.
Let us know what you find out.