Help - cannot open my SONY VAIO A297 case

[PeeWee51]

Can anybody help. I cannot find a way to access the inside of my Sony Vaio A297XP to replace a non working DVD drive.
I've undone the screws at the back and the case seems to hinge up as expected but there is significant resistance around the middle of the keyboard. Is there a 'hidden' screw or something else I am missing.
Obviously afraid to use too much force unless I break something
Thanks a lot
Tony

[mjc]

This (http://www.vaio-link.com/tutorials/memory/memory.asp?l=en&category=0&serie=VGN-A&m=1727) gives you some basic disassembly instructions to get to the memory...

[PrntRhd]

Nothing specific to that model but something here may help get the general idea:
http://repair4laptop.org/disassembly_sony.html
As you may be finding out, the SONY official user guides are woefully lacking beyond memory addition.