Zte v970 - problems with signal reception


So, I bought Zte V970 from China. This is the version with Mediatek mt6577 chipset. First I was very surprised how elegant and fast the phone was, but after using it couple days I have found complaints, hopefully something can be done. GPS in this phone model works bad and I can live with that, but I have now noticed that even the phone signal reception is quite bad and causes missed calls. When the phone is on the table for example, it works fine but if I put it in my pocket the connection is lost, atleast most of the time. We tested yesterday and it worked only in my pocket when I was outside, signal was probably good enough there.

Is there any tweaks or relatively easy hardware things to do? Rom file is V1.1R2MOD and Android -version is therefore 4.1.1. The rom has mtk engineering menu which allows you to change lots of things, I was to set maximum volume higher from there. I live in Finland in case location matters.