Android - Can't send image in base64 format to webservice over wifi

My scenario. Android application that get pictures and other information and stores all开发者_运维百科 in sqlite database. WCF Webservice that receives the picture in base64 format and the other data, all of them as string. When sending with the image via HSDPA/3G it works perfectly, but if I turns wifi up and try to send, nothing happens, until get de timeout error. When sending without the image, only other data, via HSDPA/3G it works perfectly, but if I turns wifi up and try to send, nothing happens, until get de timeout error.

Any ideias?

Thanks.

Edit:

Still can't send data over wifi.

I discovered that I can only send data that not exceeds 800bytes. I created two pictures with 800k and 900k, only the image with 800k was sent. In 3G mode works perfectly.

What could be happening?