No crashes here. I exported many characters in a row as ttf, both as Basic Latin characters and Latin-1. Using X4 on Win7 Professional.
Perhaps you guys with the problem could e-mail me your cdr files (if you are concerned about copyright issues, three characters in the file will suffice). I will try to detect where is the error lying.
Please use the attached file for testing. If after exporting all three characters your Draw does not crash, perhaps the way you are drawing the fonts is incorrect. Or the problem might lie somewhere else, not being CorelDraw directly to blame.
I have exactly the same problem. Also using coreldraw X4 on a windows 7 premium system.
Even when I used the test file from Mosh, the same crash occurred. When I select the ttf file that was created with the first export for exporting my second character, Coreldraw asks whether I want to replace it. I thought this might maybe help you solving the problem.