php - ImageMagick getImageLength() not found

Question

Initially, I used getImageSize but an error message informed me it was deprecated, and to use getImageLength instead. Then I get this error.

Call to undefined method Imagick::getImageLength()

I'm using imagick 3.01 and ImageMagick 6.2.8.0 on CentOS 5.8. I upgraded imagick to the 3.1 RC2, but the error persisted. I reinstalled ImageMagick and ImageMagick-devel and still no luck. I used yum to install ImageMagick, and then pecl to install imagick.

Any advice? Thanks.

Pastebin data from get_class_methods dump

http://pastebin.com/MUkDBJpY

Version info is below

array(2) {
  ["versionNumber"]=>
  int(1576)
  ["versionString"]=>
  string(79) "ImageMagick 6.2.8 05/07/12 Q16 file:/usr/share/ImageMagick-       6.2.8/doc/index.html"
}