A mechanical way of ejecting the disc Jim is to push a straightened-out paper clip in the small hole in the front cover of the drive. Doesn't solve the main problem, but gives you a workaround without having to reboot.
Your problem might not be mechanical at all. CD writing software must 'close' the disk before it lets go of the writer and won't let you eject until that's been done. You might try the support page for your software and see if any updates are available, or go to the writer mfg site and check for new drivers. If that fails, try deleting your writer (go to Control Panel, System, Hardware, Device Manager, DVD/CD-ROM Drives) click the "+" sign in front, right-click on the drive and select "Uninstall". Then re-boot your system and the drive should be re-recognized and installed. You may need your original install cd to complete the operation. Also try deleting the writing program and re-install it, as it may have been corrupted. Good Luck!