Do you recognise a 6 pin oled display?

I hope you are still watching this.
I import the part, heltek_oled.fzpz, see the picture of it in my parts, go to fritzing/parts/user and a file has been added
Nokia5110LCD_1.fpz (I assume this is the file, if I clear this it comes up if I import the oled file again).
I can use it and drag it around the screen fine.
When I close fritzing and open it again it is ok until I go to my parts. It then brings up a box that says
Unable to find the following part
'Nokia5110LCD_1 at 'C:/Users/Bob/Documents/Fritzing/parts/user/Nokia5110LCD_1.fpz'
I can still see the file and I have saved both the bin and the sketch before I close but having done it quite a few times after reloading it it still fails to see the part?
Any idea what might be causing this?