ARM Parallel Port Programmer Problem not detecting the target??

Helllo!!! Everyone i am using this Parallel Port Programmer
http://shop.ngxtechnologies.com/product_info.php?products_id=29

to program my LPC2148, it is a Wiggler Based Programmer and is supported by H-JTAG Software.

I tried to use this programmer with Keil Directly, but failed because i had not started H-JTAG Server, after that i started H-JTAG Server and my Controller gets detected as ARM7TDMI-S microcontroller in H-JTAG Server, after that i open H-Flasher and then program a simple code to blink LED's.
Its programs and verify properly but LED's on board doesn't work but when i reset the board by reinserting its power it works.
But after that H-JTAG Server is not able to detect the target, i dont know why??
Its works for the first time and till now it is not detecting target and giving this error.



Even if i didn't connect the hardware its giving the same error.
Please suggest me what might be the problem.

I am not able to solve the problem properly, but still its working now.
What i do is as follow:-
I thought i had used programmer/debugger and thats why the bootloader which is residing in the ARM's memory gets removed, and this might be a very bad situation for me, because i can't program my board as my programmer is not working and bootloader has been erased.
This is what i thought, but this is not the case, i tried serial interface and LPC210x Software to program my board and it works.

Now a question arises in my mind?? ARM Controllers has bootloader code when they are manufactured, am i right, means NXP has provided the bootloader code in its memory by default and we cant erase it??

Okay then i again started to use my parallel port programmer and it works this time, i debug also and it works.
I did it 3-4 times and then stop H-JTAG Server and then re-started it, again same problem occurs it doesn't recognize my controller.

Then again i use bootloader software and program board and then try the Parallel port programmer and yes it again works.
I dont know the logic behind this, its really very weird thing if someone knows why this happen then please explain me.

One more weird thing happen.
My Parallel Port Programmer will work fine, when the code present in the controller stops executing at some place.
In the above case H-JTAG Server detects ARMTDMI-S each and every time.

But as soon as i insert the code having indefinite loop, H-JTAG Server stops detecting the target.
What my be the case please someone suggest me something.

LPC2148 JTAG pins are shared with GPIO function, in so far there a various options to stop JTAG access by configuring the processor inappropriately by your application program. JTAG should be always accessible in reset state. JTAG access can be also disabled in the configuration word.

ISP bootloader can't be erased.