6600 vibration problem...

i found a problem with my 6600... when my phone is in silent mode...it will vibrate for all incoming calls...but it didn't vibrate when receive an SMS...I have checked out the setting...everything is ok...message tone is off...vibration is on.... what is going on with my phone...can anyone help?? __________________ Nokia 6600 has this problem?? I still thought of buying this phone but I will reconsider again... __________________ I have checked it out...it is a common bug in the software...it can be solve by recording a silent cound clip and set the clip as message alert in Silent Mode...then everything is solved...