Custom field dropdown list congestion

Hi,

I’m using the Mimbo theme which requires the use of a custom field (Image)to place an image in the front page.

However, since I started using the WP-Video plugin, all the videos put on the blog with it become keys in the custom field dropdown list. Now the list is so crowded and fool of youtube addresses that the Image field is not even listed! If I type “Image” in the alternative key field, it works; but even that field is getting shrinked by the dropdown list size. Check the image.

Is there a way to work around this? I believe I can’t delete the other keys or I’d lose the videos in the posts. Can’t the dropdownlist be disabled or just show the “Image” key?

Any help is appreciated, thanks.