CorelDRAW versions prior to X3 & X4 are way too old to be dealing with any of the CS versions of Illustrator. X5 is out yet I still use X4 ONLY due to a ton of macros that I have and use have not been updated to X5 yet. Some are commercial yet most are my own custom and I haven't had to time to update the VBA code.
I would HIGHLY suggest looking at at least upgrading to X4. X5 deals with Illy files a lot better than X4 though and I would guess due to release dates from X5 that the next new version of DRAW will be coming soon.
It is possible the file you have was saved with compression on. If this is the case you WILL NOT get it into your version of DRAW without the help of someone with a higher version of DRAW who can save down after opening the file.
CorelDRAW V12 is seriously out dated and lacks a ton of awesome new features as well as a lot of old bugs removed and fixed. Upgrade if you can. Upgrade price is only $195 US, I believe which is honestly not that much.
If you still need help with the file I will convert it for you. Only problem is I am heading out of town around 3 AM and will not return until late Saturday night. If you need it fast please send it to me now. If it can wait until Sunday let me know and I will get it to you then
richard@fluiddsn.com