Gx1 iso 3200 write speeds to SD card

I have an issue to nitpick about the gx1 in that the write speeds to card is super long when I shoot at ISO 3200.

When I shoot at ISO 1600 the lag is barely noticeable, but at 3200 it is very obvious.

Is there something wrong with the camera? or is this inherently a design in the gx1's sensor or camera?

compared with my gf1, it has no problems shooting at iso 3200, and doesn't exhibit the same lag.

(i am not mentioning photo quality here, but only the write speed of my gx1 when shooting at iso 3200 and above.)

is the gx1 doing some in-camera processing at or above iso 3200 that makes it a little slower in shooting the next frame compared to iso 1600?

 

thanks for the replies guys, actually i have tried a number of iso combos, raw and jpeg shooting, and it really is apparent in all conditions. I have even tried iso 2500, and there is a very noticeable lag or a longer write time for any ISO above iso 2500.