Imported Ultrabeat Wav files playback high pitch sound

Hello!

I'm new to Ultrabeat.

I have no problem dragging and dropping Ultrabeat aif files in the oscillator box, but when I drag and drop wav files into it they play back as a high pitch sound.

I've got some great accoustic drum samples from an FXpansion library... They sound fine in the browser preview, but can't get them to work in Ultrabeat.

please help!

thanks