Have you tried reinstalling the two SD Card/MemoryStick Drivers?
There are no memory card drivers for Windows 7, so I would try reinstalling the Original Windows Vista drivers. You will find them under 'Preinstalled Drivers and Utilities' on the support pages for your Vaio here: -
The original drivers for your model are Vista 32Bit and if you have upgraded to Windows 7 64Bit then this is not supported by Sony for your model.
If this is the case you will need to source the Host Controller drivers direct from the manufacturer. To find the manufacturer open Device Manager and have a look under Disk Drives or IDE ATA/ATPI controllers – you may find that it is Ricoh. If so have a look at this link.