I have noticed it also. (the green led thingy) but, when I addd some cooling ... it does not longer happens. So I think maybe the BE100 is overheating?
Also on my 108BEE's farm it happens from time to time. But it is a very short strong bleep.

Right now at 16Mhz 458 448 Mhz one on 1.4V the other on 1.3, Can tell right now wich one is which after 13 hours... it seems that its working but replace the crystal is darn hard.