Works just fine with dev board. Our board - different story. Is there a max external osc. that may be used if you plan on using jtag? Ours has 48 Mhz, connected only to XTAL1 in the described manner. The eval board uses 12 Mhz, which is the only real diff.
I tried that yesterday - no dice.
I have figured out that the JTAG interface is disabled if pin P0.31 is pulled low after reset for LPC2138. This is not documented in Philips manual. This problem can easily be duplicated with MCB2130. If pin P0.31 is pulled low with 20Kohm resistor after reset, JTAG interface does not work.