How do I prevent an uneven edge?

Gents,

I have been having mixed results with my new (and first) straight. The razor felt like it was dragging during parts of the shave and passed easily in others. Then it suddenly dawned on me... perhaps my edge wasn't uniformly sharp!

It turns out if I do a series of hanging hair tests starting at the point and progressing towards the heel of the blade, it starts to fail for about the last 25% of the edge (ie the hair just bends).

I am using one of Tony Miller's 4-sided heirloom paddle strops and a (Dovo 5/8 also supplied by Tony). The paddle has 3 grits (3, 1, .5) an a stropping side.

I assume that I have sharpened or stropped the blade incorrectly. Any suggestions on how I can fix this? Even more importantly, how can I prevent this in the future?