Question about Sage Software ACT!

User cannot open ACT! 9 (2007) database today, but had no probs yesterday. Other users on other PCs have no problem. Created new user profile on same PC and that user can open db w/o problem. Db is hosted on separate PC. Error message is, "The database could not be accessed. In order to access this database, check your network connection and verify that your database server is available. It may be necessary to disable any firewall software." I tried MOST of the steps in http://kb.sagesoftwareonline.com/app/answers/detail/a_id/19640, but quit when I found that I could access the db from a new user profile. Any tips?