Try this:

Quit QuickBooks and go to the finder to throw away the preferences. Sometimes they get corrupted.  In the finder hold the option key and choose:

1. Go-Library

2. Open the Preferences folder within the Library folder

3. In the search field on the finder window that appears type com.intuit.quickbooks

4. This should filter the window down to just the files that begin with com.intuit.quickbooks - these are the QuickBooks preferences.

5. Select the all and drag them to the trash.

6. Launch QuickBooks.  It should come up with no files or windows remembered.

7. Try opening your company file.