Losing connection during call. Check the image

[freaknormel]

Hello.

Sometimes, i am losing connection while on the phone. After the some seconds, i can hear a sissing sound. The call counter keeps going. I am using Maverick Rom 4.0. I had same with my previous Droid 3 device.

Using T-mobile, from netherlands, the phone is unlocked.
Here is a screenshot:

https://www.dropbox.com/s/nqeryuifa4...bb129ca5d6.jpg

Thanks for the help