Importing tends to be an imperfect business.  Try this instead:

1)  Create a new .PST file in Outlook at work -- use File | New | Outlook
Data File.  It will open in your Folder List.  If there isn't already a
Calendar folder in it, create one.

2)  Switch to a table view of your original Calendar folder -- one like By
Category, which doesn't have any filters set on it.  Select the items you
want to copy and right-click and drag them to the Calendar in the new .PST
file.  When you've finished copying, close the new .PST file -- right click
its root folder and select Close.

3)  Copy the .PST file you created to your hard drive at home and make sure
it's not marked read only.  In Outlook, use File | Open | Personal Folders
File to open the .PST in your Folder List.  Now you can copy the items from
that Calendar folder to the one in your original home .PST file.  Close the
unneeded .PST file out of Outlook when you're done.

Do you get better results this way?  Post back and let us know.

I have tried your suggestion and I believe I'm seeing much bette
results.  

Thanks for your help