Hi
Check to make sure that the MAX232 is doing the 'voltage conversion' from TTL to RS232 (and vice versa) properly. You can use an oscilloscope for convenience, but this can also be done with a multimeter.
Also check to see if your terminal software expects any handshaking using RTS/CTS? If this is the case, you should turn it off or set it according to the uP's external UART configuration.
Finally, though unlikely to be the case, check that the serial port configuration is set properly in the terminal utility (i.e. port address (COM1..4), IRQ, etc.)