I have a number of your I2C/SPI backpacks and several different lcds (188, 198, 16x2 RT162-7 (not sure of ada product #))
Starting to dig into them again (as the TFT-Touch is no good on mega - per other thread)
Alas the tutorials have moved and now you have to navigate through several levels of "Tutorial Has Moved" to get to one of the relevant tutorials.http://learn.adafruit.com/character-lcds
or digging to the I2C tutorial... http://www.ladyada.net/products/i2cspilcdbackpack/
Perhaps this is an in-process move from ladyada.net tutorials to the learn.adafruit.com site?