CD-ROM frozen shut!

I don’t know if I put the CD in uncentered or what, but all of a sudden, and for the first time in the 4 years I’ve used it, my CD-ROM is stuck closed with a CD disk in it.
I’ve clicked “eject” on the right-click-mouse menu, pressed the “eject button,” and even inserted a blade carefully under the cover plate to exert a small amount of pressure as I pressed the button, hoping to give it a bit of an extra nudge, but nothing has worked so far. Any ideas? (It is a Hewlett-Packard “CD Writer Plus,” 9300 series,internal CD-ROM.) Thanks in advance.