Which map do you mean with version 945, please.
In the first place Navcore 7.903 is a way out of date.
I suggest to install 9.510 for 32mb devices.
If your device use an SD card, update your Bootloader to 5.5128 than you're able to use SDHC up till 32GB
From that moment on you're able to store the whole world on your device.