IKEA Kallax 2x2 wiggles a bit -- is this normal?

I just built an IKEA Kallax 2x2 shelf and loaded it full of records. It looks great and seems pretty stable overall, but it can wiggle a little bit side to side if I push it. And I mean a very little bit -- perhaps a millimeter or so.

Is this normal? I know it's a cheap IKEA shelf, so I'm not expecting the sturdiest shelf in the world. But have others experienced their Kallax units -- even the small 2x2 ones -- wiggling a tiny bit once assembled? I don't want my shelf to collapse and destroy my records.

 

No they should not be wiggling. Did you screw everything tightly?

 

I put white tile board(shiny surface) on the backs of mine. nothing moves

 

I unloaded all my records. Tightened all the bolts again. Put all my records back. It barely moves now. Sure, if I press on it there's some give. But it seems much sturdier. Thanks!

In related news, I have room for about 8 more records in the entire shelf. Guess I'll be building another one soon!

 

I used wood glue while assembling, and added a thin plywood back. Very sturdy now, and LP's can't be pushed out the back.