Default can't install any apps after flashing custom rom on my xperia x10 mini pro

i recently flashed my sony ericsson x10 mini pro with ArcMiniNxT6 with latest nAa Kernel ,and the installation was fine and i booted into my phone properly the problem is whenever i itry to install any apps it says The application ( has stopped unexpectedly. Please try again..this happens for every apps what is the problem ,i have google apps already installed on my phone with the rom as i can see market app on my phone,any solutions?