Illustrator has become slow in only one layer.

Hey!

I'm completely new to illustrator and have been doing some painting in the program. After painting I have been editing my lines using the direct selection tool which has now become very slow.

The piece i'm working on is not a big file and my only other layer (the fill) works perfectly fine, even with the direct selection tool. The document raster effect settings are set to 72 ppi and I have tried using another user account but encounter the same problem.

I'm sorry if any of this is unclear etc.. I'm still learning my way around the basics.

Thanks,

Alex