I'm not sure if it's an issue with my Desire or my sim card or network (T-Mobile). Basically, I will have a full signal but if a person tries to call me will be forwarded to my voicemail. I will then receive a text informing me that I have a missed call. Also, when calling a contact, there will sometimes be a long delay before it finally connects and begins to ring. Has anybody else had either of the above?