Changing phone adapters

I believe that some of the problems I am experiencing are related to my PA (a Linksys PAP2T, I think, the original one provided by VOIPo). Everything works fine for a while after rebooting but then issues come back. Rebooting it again seems to resolve the issues for a while and then the cycle has to be repeated.

So, assuming that it is to do with the PA, does anyone have recommendations on what one to try? Another one of the same? Something different? Something to avoid?

TIA,
Tim W.