pokemon platinum underground error

i keep having kind of error ever since i got the explorer kit. i was just wondering of anyone has experience this too and how to fix it. going underground works well on pearl and diamond. i'm using no$gba 2.6a with no$zoomer.

"a communication error has occurred.

you will be returned to the title screen. please press the A button."

- this is the error message that appears when trying to go under ground.