Did you manage to fix your problem? I have what looks like the same issue.
wrote 1568 byte from file main.bin to flash bank 0 at offset 0x00000000 in 0.953125s (1.606557 kb/s)
target state: halted
target halted in Thumb state due to breakpoint, current mode: Supervisor
cpsr: 0xa00000f3 pc: 0x7fffd2c0
checksum mismatch - attempting binary compare
Verify operation failed address 0x00000000. Was 0x34 instead of 0x18
This is the first time I have tried flashing the chip via JTAG.
My set up:
Embedded Artists LPC2148 Education board
WINARM
JTAG - Olimex ARM-USB-TINY
Openocd-r1888
I’ll keep plugging away and let you know if I find the problem.