I have been using Construct for a day now and i am pleased with it, but i am having some problems with it.
1. Decreasing RAM.
My RAM looses 1MB every few seconds, even after i free it (using MaxMem). And letting Construct run too long makes my system unstable (Around 40%)...But this happens with Hammer as well (Half Life 2's Map Editor) and i think it has something to do with my system.
2. "The instruction at 0x00000000 referenced memory at 0x######## The memory could not be 'read' "
Ohhh, i hate this one, it makes Construct crash, along with my Source games. This might also be related with the problem above, thus it just being my system...
Thinking more about it. Have you considered doing a proper memory test? You can find various utilities to do this via Google. It could well be a bad memory stick. That or your drivers need updating, and DirectX reinstalling.
Edit: Maybe also run a test of your hard drive/s especially the one your swap file is on. Could be a bad block that happens to be where the swap file is located, resulting in it becoming corrupt, and more likely to happen after as you say, construct has been running a while, giving it time to have been swapped back and forth as you did other things. Though I think the memory issue is more likely, that or drivers.
It could also be a problem with the PSU not being powerful enough for the system, but that's not as likely in this case.