I was having a similar problem. I tried the solution above which lead me to my final solution.... After renaming the msmapi32.dll file to msmapi32x.dll, I opened Outlook 2003. Outlook automatically replaced the msmapi32.dll file through setup. Outlook provided a message that the Outlook.ost file for the user was damaged. Next I ran the inbox repair tool. scanpst.exe repairing the outlook.ost file. Info on running the repair tool is in QB Article 287497. Hope this helps....