I've just checked the application log on the AOS server and noticed the following at the time I last experienced this issue:
Object Server 01: The database reported (session 78 (BoydS)): [Microsoft][SQL Server Native Client 10.0]Communication link failure. The SQL statement was: "SELECT T1.ACCOUNTNUM,T1.CASHDISC,T1.CREDITMAX,T1.CURRENCY,T1.CUSTGROUP,T1.INVOICEACCOUNT,T1.PAYMMODE,T1.PARTY,T1.PRICEGROUP,T1.ENDDISC,T1.MULTILINEDISC,T1.LINEDISC,T1.LINEOFBUSINESSID,T1.CUSTCLASSIFICATIONID,T1.JOBCOMPLETE,T1.DEL_NAME,T1.RECVERSION,T1.RECID,T2.NAME,T2.RECID,T2.RECVERSION,T2.PARTYNUMBER,T2.NAMEALIAS,T2.RECVERSION,T2.INSTANCERELATIONTYPE,T3.LOCATOR,T3.RECID,T3.RECVERSION,T4.LOCATOR,T4.LOCATOREXTENSION,T4.COUNTRYREGIONCODE,T4.RECVERSION,T4.RECID,T5.CITY,T5.COUNTRYREGIONID,T5.COUNTY,T5.DISTRICT,T5.STATE,T5.ZIPCODE,T5.RECID,T5.RECVERSION FROM CUSTTABLE T1 CROSS JOIN DIRPARTYTABLE T2 LEFT OUTER JOIN LOGISTICSELECTRONICADDRESS T3 ON ((T3.PARTITION=?) AND ((T2.PRIMARYCONTACTEMAIL=T3.RECID) AND ((1=? OR (T3.ISPRIVATE=?)) OR (T3.PRIVATEFORPARTY=?)))) LEFT OUTER JOIN LOGISTICSELECTRONICADDRESS T4 ON ((T4.PARTITION=?) AND ((T2.PRIMARYCONTACTPHONE=T4.RECID) AND ((1=? OR (T4.ISPRIVATE=?)) OR (T4.PRIVATEFORPARTY=?)))) LEFT OUTER JOIN LOGISTICSPOSTALADDRESS T5 ON ((T5.PARTITION=?) AND (((T2.PRIMARYADDRESSLOCATION=T5.LOCATION) AND ((T5.VALIDFROM<=?) AND (T5.VALIDTO>=?))) AND ((1=? OR (T5.ISPRIVATE=?)) OR (T5.PRIVATEFORPARTY=?)))) WHERE (((T1.PARTITION=?) AND (T1.DATAAREAID=?)) AND ((T1.ACCOUNTNUM=?) AND (((T2.NAME=?) AND (T2.RECID>=?)) OR (T2.NAME>?)))) AND (((T2.PARTITION=?) AND (T2.INSTANCERELATIONTYPE IN (?,?,?,?,?,?,?) )) AND (T1.PARTY=T2.RECID)) ORDER BY T2.NAME,T2.RECID OPTION(FAST 3)"
I'm not sure if this was thrown when at the time the user attempted to open this form or when I killed the process on SQL Server.