Problem description: 
A line with transparency of 50% or greater cannot be animated with the Wipe effect.  Instead, it will simply appear after a delay.

Steps to reproduce:
1. Using one of the Polygon drawing tools, draw a line on a slide.
2. Increase the width of the line so that it's easy to see.
3. Use the Format | Line menu to change the transparency of the line to 50%.
4. Under Custom Animation, click Add.  On the Entrance tab, select the Wipe effect.  For Speed, choose Slow.  Click OK.  Make sure that Start has On click, that Direction is appropriate for the direction of the line, and that Speed is Slow.
5. Click Slide Show or press F5.  Click the mouse.  After a delay, the line will appear, but it will not wipe.

Current behavior:
Lines with transparency of 50% or greater do not animate, they simply appear after a delay that is roughly the same as the time the animation would have taken.  Lines with transparency less than 50% work correctly.  (I have tried Wipe, Peek, Venetian Blinds, Pinwheel, and Boomerang, and they all behave the same.)

Expected behavior:
A line should animate the same regardless of its transparency.

Platform (if different from the browser): 
MS Windows 7 Pro, v6.1.7601 SP1, on Dell Inspiron 620 (Core i5-2320).  Built-in Intel HD graphics.
              
Browser: Chrome/19.0.1084.46