Outlook 2007 Calendar

Tech Support Guy System Info Utility version 1.0.0.2
OS Version: Microsoft Windows 7 Home Premium, Service Pack 1, 32 bit
Processor: Intel(R) Core(TM) i3-2120 CPU @ 3.30GHz, x64 Family 6 Model 42 Stepping 7
Processor Count: 4
RAM: 3481 Mb
Graphics Card: Intel(R) HD Graphics, 1548 Mb
Hard Drives: C: Total - 276837 MB, Free - 121706 MB; E: Total - 199998 MB, Free - 130480 MB; F: Total - 2861575 MB, Free - 2609945 MB;
Motherboard: Gigabyte Technology Co., Ltd., H61M-USB3V
Antivirus: Kaspersky Internet Security, Updated and Enabled

I use Outlook and have an IMAP account. My calendar appointments have disappeared from the main view but I can see them on my iPhone. If I change the current view to 'all appointments' they are listed but when I go back to 'Day/Week/Month' view it is empty. I can only see items in these views: All Appointments; Active Appointments; By Category and Outlook Data Files. I can also log into my calendar in iCloud and see the same appointments there. I have run scanpst to fix any errors but still can't access appointments on PC. Any ideas?