We have the same problem.  The AR module is almost useless.  Can't lookup customer alphabetically.  Can't print an invoice.  Statements are sometimes correct, sometimes not.  Is bringing over balance forward credits that are not correct.  It is a mess.  We are considering installing the prior version on a separate computer and trying to use a backup from December.  It is awful.  We stopped posting in it until we can figure out what to do.  It is time to send out bills and statements and it is basically not functional.