Yes, I too also have to agree with Nixer6 on his certain conclusions.
I too have had crashes only when Ia Drang (other OFP maps to) was loaded with too many units or vehicles that my computer's Ram couldn't handle along, with my video card which is a Geforce 2 GTS 32mb.
My other conclusion is that since OFP: Resistance, as Nixer6 mentioned, is very demanding on your computer with certain maps, with the terrain, also due to the large maps that OFP has, loaded along with units, vehicles, unofficial addons all loaded on, "suck" up a lot of your RAM. Along with the graphics on some addons are very nicely textured, which also once again put stress on your video card and RAM. Therefore the more units, vehicles, and what not loaded on a map or while map editing, people with the "weaker" hardware accessory, such as 128mb, 256mb, and even 512mb Ram, is not enough for games nowadays demanding and relying on a lot of the computer's hardware accessories. Also not to mention computer owners with 32mb, 64mb, and 128mb video cards will crash too, but most likely a certain group will experience more difficulties than the other, such as the game crashing.
There are couple of options, more RAM 1GB and 2GB option, better video cards, which currently are ATI Radeon 9700 128mb and Geforce 4600 Ti 128mb, will most likely help the performance. Also processors play big roles in certain scenarios where maps are heavily loaded, slow processors will not be able to process the information fast enough for better performance during game play, but on the other hand faster processors such a 2.4Ghz or now 3Ghz processors shouldn't "struggle".
My belief is that the shortage in Ram and Video Card Ram, because of the too many operations that are going during game play and in your background (consider the shutting down of couple of programs in the 'End Task' menu, not the important ones though), ones computer cannot handle, thus causing it to crash or other malfunctions, but remember this is all a theory, not a fact.