I'm assuming that you're talking about the cursor in a web browser or word processor or anything that uses that really skinny cursor. I'm also assuming that the cursor blinks, but it does an up-down motion instead. Please correct me if I'm wrong.
I think that's an issue with the open source video driver. I've had that happen before, and since you're running an nvidia display, go to rpm.livna.org & get the yum repo. Afer that's done, type yum install kmod-nvidia. Using nvidia's official drivers fixed it for me.