need some expert advice on what a telco tech called a timing issue. we have an asterisk pbx with a digium t1 card and it has been dropping a number of calls over the last two days and we're not sure what the cause is.

we had a verizon tech come on site yesterday to test the pri and he said that he was seeing a timing issue. he recommended that we restart the pbx which eliminated the issue but he only tested for a minute after the restart so i'm not convinced that there isn't some other issue. before we restarted the pbx he actually told me that he noticed a number of errors on the circuit but he wasn't sure if they were related to the timing issue.

does anyone have any recommendations as to where we should go from here?