I currently have a DVI monitor plugged into a VGA graphics card via an adapter. Just recently I have had problems when starting up my computer, as the moniter shows a message "No Signal". It appears that the computer continues to start up even though there is no picture on the monitor. On further in vestigation when I move the adapter about and restart, I can eventually get the monitor to work, and this is indicated by a singal short bleep from the computer. At all other times I get a long bleep followed by a short bleep and the monitor fails to operate. Any suggestions?