Hi
Can you post a link to the instructions that you are using? Chuck is right that the steps you mention do not tally with the steps on the Besta Burs TV unit.
One thing I will say about the Besta is that you have to be extremely careful to ensure that you assemble the parts the correct way.
If you find that some parts later in the assembly don't seem to want to fit it is almost certainly because you have gone wrong earlier.
Look at the instructions very carefully and check that all the holes are in the right places. Step 3 (of the Besta Burs TV unit instructions
http://www.ikea.com/ms/en_US/custome.../B90103758.pdf) is where it usually starts to go wrong.
I hope this helps.