Are you positive that the hex file you are uploading starts at 0x2000 and not somewhere else? Try getting the following zip file from the PJRC site:
http://www.pjrc.com/tech/8051/board4/blink_asm.zip
Unzip this file and upload the .hex file to Paulmon and see if you still have the same problem with memory.

As for the "C" command, it should clear RAM. Type "C" and then specify 2000 to 7fff for the addresses. The command should complete successfully (no errors) and then when you look at memory in this range using the "E"dit command it should be all zeros.

If these tests work, the hex file you are creating is not originated in memory at the right location. If the tests do not work, then it sounds like a hardware problem. If it is a new board and that is the case try contacting Paul or whoever you purchased it from. Explain the results to the above two tests and that you think the board is defective.

Frank Kienast