Strange Problem

I had a very strange problem with my trixbox in my office, the problem is my server will fail to call out to PSTN line every an hour or so. The phone tone is a waiting tone but the targeted phones just won’t ring. I will have to restart my server if i ever need to call out since then. I am using a Digium TDP-110 with a E1 line so is rthere any problem with the card as i heard there was a recall for the product.