I was reading in the forum earlier and ran across something about the dome light circuit first running through the alert buzzer. From what you have described it seems that this could be related to your problem? Id check this to see if it is in any way related to your flashing dome lamp.

__________________
1983 Mercedes 300SD
1987 Mercedes 300SDL
2001 VW Passat 2.8 AWD
2007 OM642 Jeep WK 4x4