If the crash report says it's out of memory, it's out of memory. Really your only options are to either disable MFFS (It can eat up a bit of RAM, hence why it would crash) or more preferably, upgrade the RAM. Check out this stickied thread about hardware. A decent host usually gives you at least 4GB for around $25. per month, of course I recommend more if you plan on having more than 15 people.