Wooden Doors in spawn-protection can be opened but not passed through

Scenario:

minecraft 1.5 pre-release SMP
Added OP "notch" to enable spawn protection
changed spawn-protection to 150
joined game
opened wooden door (can be opened)
tried to go though (cant do that)

Wooden doors can be opened directly (right-click) in spawn-protected area OR seem to open for clients but cannot be passed through. Will stutter like stuck in block if tried.

Doors with wooden pressure plates act normally.

Visual glitch?

Edit:
It's visual, relog and doors are closed.