Yet another Civ IV Issue

Ok. Where to start this story...

Like Metalarif, I too now have a Dell XPS M1530 and have installed Civ IV. For the first few weeks, it ran like a champ. This was after running it on my old Dell and the video card limitations causing it to crash a lot. Just recently it's started coming up with this error as either it tries to Autosave, or sometimes when I save it, where it says: "Memory Allocation Failure - Exiting Program. Reason: Bad Allocation.File.\CvAppMainLoop.cpp.line!261"

Now, to me it seems like some sort of obvious memory failure, which also seems rediculous considering that I have 4Gb of RAM and just a few Gigs (300) of storage. The problem is I have no idea what to do about it. I've tried adjusting all of the graphics settings to run on the lowest of levels, but to no avail. The other thing I noticed is that it started doing this only after I used the WorldBuilder feature a few times and changed things here and there). Not quite sure why this would matter since it's a normal feature in the game, unless it was just too much changed at once. But again, this system should be able to handle that and the top graphics with ease.

Any guidance would be awesome, since (I forgot to mention) I've gotten no response in three days from 2K Games.