So einfach ist das nicht, in den Bascom Samples fehlt oft das I2CInit.
In der Hilfe steht:
By default the SCL and SDA pins are in the right state when you reset the chip. Both the PORT and the DDR bits are set to 0 in that case.
When you need to change the DDR and/or PORT bits you can use I2CINIT to bring the pins in the proper state again.