Dxf import problems.. Anyone have any idea??

As I've done hundreds, if not thousands of times before, when I need to email a PDF of a router file, I export a dxf from my router software and import it into Corel. I do this at least 10 times a day. My router software cannot export a PDF.  Today, after having imported about 5 dxf's, Corel suddenly stopped importing them. All I get is an "unrecoverable error" pop up. I did not make any changes to my import filter. I've tried several different dxf's as well. I can't even import dxf's that  have worked in the past. I rebooted my computer. No difference. Still wont work. I was able to import the dxf on another computer running Corel x6 with no issues at all. So I know the file is okay. As far as I can tell, the problem is either my computer or Corel on my computer. What I don't understand is how was it working perfectly fine one minute, and not working the next? Everything else is working just fine. No problems other than importing a dxf. Has anyone ever encountered this? If so, how did you fix it? Using somebody else's computer to do this is not an option. The other guy needs to work too..  ;)