I know the feeling:
I was at a Casa de cambio in Santo Domingo last year, and upon hearing me speak, the folks there asked if I was "Peruvian or something." And no matter how hard I tried to convince them that I was born and raised in the Cambel?n sector of Hig?ey, they continued insisting I was a foreigner. (If they only knew I could do a killer Jimmy Stewart, a Pakistani gas station owner, and an unequal Forrest Gump... all rolled into one. I reserve that for my American audience.)
In Texas, other Latinos have said, "Usted no parece dominicano." I think they are accostumed to watching dominicanos peleando en el Show de Cristina y Caso cerrado.
However, while I'm hanging out with buddies, I'm at my best chopo:
D?melo, ke lo ke, maltido pariguayo del diablo?
Aqu?, ya tu sabe: trag?ndome un cable, pero no e' tu culpa.