This guide won't go into the actual export of a VirtualBox OVA with the intended use for a VMware ESXi 5.5 environment. It won't even use the conventional tools that some sites suggest; however, this method worked for me.
After repeated failure attempts to import a VirtualBox OVA, I used 7-zip to extract the contents (ignoring any error or warning message) into a folder. Once the contents were extracted, I used my favorite text editor to modify two files. The two files that are of interest are the ones with the extension "ovf" and "mf".
The "mf" file contains the SHA value for the "ovf" and "vmdk". I simply deleted the the line containing the "ovf" value and saved the file.
Then modified the "ovf" file for several values. Since this was a CentOS install, VirtualBox used the value "RedHat_64" and ovf:id of 80. These two values changed from 80 to 107 and RedHat_64 to centos64Guest.
<OperatingSystemSection ovf:id="107"><vbox:OSType ovf:required="false">centos64Guest</vbox:OSType>
Change the VirtualSysemType.
Change the values for the Controller from SATA to SCSI using the following values.
<Item> <rasd:Address>0</rasd:Address> <rasd:Caption>SCSIController</rasd:Caption> <rasd:Description>SCSI Controller</rasd:Description> <rasd:ElementName>SCSIController</rasd:ElementName> <rasd:InstanceID>5</rasd:InstanceID> <rasd:ResourceSubType>lsilogic</rasd:ResourceSubType> <rasd:ResourceType>6</rasd:ResourceType></Item>
Once these changes were made, I saved the "ovf" and the import was a success.