SUBSIM Radio Room Forums - CTD when using stadimeter

Hello,
I am new to this forum and game.I insteled SH4 on my laptop runing Win7 ultimate 64bit and works fine except when i need to use stadimeter.When i align the ship with the mast for stadimeter and left click to confirm it i gor CTD.like if i had presed exit buton.comes mesage that windows is searching for solution to problem but nothing abou it..
I have 2GB of ram and GeForce 7000M graphic card.Any solution to this problem?
BTW the red litle buton on left side on periscope i think called movment trac or something like tht shoi that thing follow alone with periscope my target in movement or i have manually allways keep ship in centerr of periscope??