Software control of MAX232 power: The problem is, if it's switched by the PIC, then a bad programming cycle (somebody trips over the cable, battery was low, etc) will leave the bootloader code intact, but the program code is screwed. So, you reset the system and it tries to execute the nonexistant program code, which doesn't know to enable the MAX232 anymore. The bootloader, which could have reenabled the MAX232, will not execute without the MCLR signal from the MAX232!