Unless you have a very specific need to have a dual-boot Virtual Machine it typically is not advisable because as you see if doesn't work properly.
That said, on the occasions I needed to use a dual boot Virtual Machine because I was building dual-boot Physical Machines and needed to test some things virtually before doing it physically I used two separate .vmx configuration files and started the Virtual Machine with the appropriate .vmx configuration file as needed.
I'd suggest you do the same! 
Copy the existing .vmx configuration file to a new name, like Windows 7 64-bit, and then add it to the Favorites/Library and then edit it to change the OS from Windows XP to Windows 7 64-bit and then delete the Virtual Ethernet Adapter and add it back. This should resolve all but the SCSI and that may be a bit more difficult and will need to see the vmware.log file to advise further. Archive (compress) it and attach to a reply.
Message was edited by: WoodyZ
A word of caution with using more then one .vmx configuration for a given Virtual Machine means you cannot suspend it or have snapshots as the configuration files will be out of sync. If you need to be able to suspend and have snapshots then you'll need to use one .vmx configuration file and will need to install the e1000 NIC Drivers in Windows XP and again with the SCSI need to see the vmware.log file.