[Question] Screen blank when making phone calls

[bobtheboor]

I just found a fault with my W200S. The screen is blank when making & receiving phone calls. My son made a call and said screen was blank and he could not hang up. I did not notice as I always use bluetooth headphones and press button on side to answer phone. When I call someone I call from phone book and put phone back in my pocket, I have flip over cover so after calling do not look at screen. When call ends audio book resumes. Any ideas what is the problem?