So, manual for the Symphony headunit in my MY09 A4, states that a 4GB SD cards will work, well, I have a 2GB which does, but the 4GB SDHC I recently purchased will not read on the headunit. is this because the headunit can't read a SDHC card, and i should use a 4GB none HC card, as my 2GB card is not a HC card? Or has the handbook just got it wrong?