Chances that anisnmp.conf file has corrupted, if you have a good copy then replace it and if not then verify what does your snmp setting look like, if it has some wierd charactors then make it to simple (just for test) and then save setting.
How did you reintialize the ANI db, only use this script if reintializing the ANI db. (reinitdb.pl -restore). Hope this helps.