Steven,
There were some bugs found and fixed in 2.5 version regarding CSV input.
So step 1 would be to download the BETA 2.6 version and install it and try again.
Here is all of our releases thus far:
You want the openrefine-win-2.6-beta.1.zip for your Windows system.
Also, be aware that you make have some weird chars in that CSV file that are causing an issue, or if the CSV is especially large. (we fixed a few bugs in that regard)
Make sure to also try unchecking the box "Parse cell text into numbers...." which might be causing an unnecessary slowdown in your case if the CSV file is large. (you can always do column datatype conversion later in the project grid, so don't worry about conversion at the beginning of importing a file, but set the unicode char set, if you know it's ASCII, or UTF-8, etc)
Let us know how 2.6 works out for you, or if you have any more questions !