dota-2
When I buy items that can be crafted, they are crafted immediately. Sometimes they are crafted too soon, into things I don't actually want. For example, I sometimes end up with power treads or a ring of basilius when I'm really building toward something else.
Is there a way to stop your guy from crafting items automatically? Or do you just need to buy your items in a different order?
It seems a bug. If your game history, as suggested by @yx in comments, registered the matches as wins for your team, submit the bug to Dota 2 Beta dev forum. Copy down the IDs of your matches to let the devs check easier what went wrong.
Update as of 18/1/2013
The options menu has been changed to make it easier to find the control rebinding for items. I have taken a new screenshot - simply click on steps 1 through 4 from anywhere in the game client to open up the menu and rebind your item hotkeys.
Note: this part of the answer is outdated, but I left it alone for now. If it's appropriate to delete it, mods are welcome to do so.
You can change the key bindings for both abilities and items by clicking their icons underneath the list of controls in the options menu. Below is a screenshot of the controls menu, you can see that I reassigned my items to numbers 1-4 and my extra mouse buttons.
It is not immediately apparent that these buttons which look like the ingame HUD are actually additional key binding options, but each one that is labelled can be changed.
It's also highly recommended that you rebind at least a few control group keys to something else, but it's rare that you will need all 6 control groups in a normal game. I chose F1-F3, but you can use whatever you like.
Best Answer
You have to pay attention in what order you build your items in order to don't built something you don't want. However be aware that some items can be disassembled when you have built them by mistake