WTX error (target gopher error)

When I download my app image (a.out about 22M ) from net and load it to
run useing loadmoduleAt, it runs, but I get a error msg like "WTX error
(target gopher error)" when I type in shell "memShow" , and a task in
my app suspend when it alloc memory .

but if i don't use loadmoduleAt , I download my app image to the board
using tornado and call app's entry function to run , it works good

I use loadmoduleAt like it's example:
pText = 0x800000; /* address of text segment */
pData = pBss = LOAD_NO_ADDRESS /* other segments follow by default
module_id = loadModuleAt (fd, LOAD_GLOBAL_SYMBOLS, &pText, &pData,

I am not sure the means of "0x800000", is it must be changed to apply
the board's memory ?

someone can help me?