I have been following a tutorial on youtube regarding building a minecart station. Now I have had no issues whatsoever until I hit the cart loading sectionunlike in the video (19:19 onwards), everytime my Pistons extend or retract, the rail keeps popping and turning into a drop. Any ideas on how to fix this would be awesome, world save can be provided if it will help with the fix.
Unfortunately, it does seem that some update between 1.4.7 and now has broken this particular aspect of the design. But it's a rather simple fix if you want to continue with this particular Pez Dispenser design (referred in the video as a "cart hopper"). You just need to send the cart forward above the hole where your cart hopper is. The simplest way to do this is like this, with a powered rail pointed towards your cart hopper. You can extend this rail however you like (you can even connect it to the arrivals line, and have it sent back to the cart hopper when you get out of the cart using a pressure plate).
However, some of the recent updates have given redstoners some interesting options with Minecart dispensers; the old Pez Dispenser design is no longer necessary. One of my personal favorite designs these days that combines cart launcher and cart retriever is this one:
When you push the button, the dispenser dispenses a cart, and launches it (be quick to catch it, or you can use a powered rail and a tripwire down the line to have it wait for you). When you come back, break the cart, and the hopper will pick it up and put it back in the dispenser. You can hook this bad boy up to whatever track switching mechanism you plan to use, and you're set.
You need to put a block down in the place where the piston will be when full extended.
When the piston extends, it will PUSH the rail; you need to have a block where the rail can adhere when it is pushed. Its impossible to keep the rail in place if the block you put is a transparent block like a torch, leaves, glass pane, etc.
Please post screenshots for more specific advice.