fldigi showing strong signal on scope but nothing being decoded
I'm using fldigi 3.21.72 on ubuntu 13.04 and am very impressed with it.
I mainly use it on psk31 which is most popular amongst the other hams.
Sometimes I'm manually scanning the frequencies and I come across a very strong signal on the scope but there is no trace of it in the waterfall nor is there any message being decoded. I was wondering if some one could explain? I have uploaded a screen shot of it to the yahoo group called fldigi.screenshot.png