clicks and pops

I am new to this forum but not to N-track. I recently upgraded to lthe latest version so I could have interface with my Tascam US-428. It seems to work fine, except I hear pops and clicks in random areas while playing and recording. It doesn’t seem to be recorded that way as I can play it back in the old version Ntrack and it sounds clean. Can anyone help?

go here -

http://www.tascam.com/details;9,15,138,19.html -

there is info on compatability problems that may help

Dr J