Originally Posted by Lord of the Rings

The file will have the same hash details as the one you already have in your incomplete or download folder. The main file name may be different but all other details such as file size, file content, etc. will be the same. Keep in mind some people rename song files after they download them. But the basic hash of the file they are sharing back is the same.

With the overwrite feature, you have options. One you can set permanently, the other temporarily. The latter, right click the file & choose save as & choose append file name.

I use the permanent setting where LW automatically appends the file name. Adding a #1 at the end of the file name so it doesn't conflict with the other. Sometimes names clash but the file content/size is different. But sometimes the file is the same.
To choose the permanent options, go to LW"s menu bar, Tools > Options > Saving > Advanced & you will see 3 options. What you prefer is up to you. I prefer the Append option personally, but then I later need to go thru & double-check the files are not identical.

Last point, why the file wouldn't play ... it might be a corrupt file. T3 Spammers; mp3 Bit-Rates Versus File Sizes (click on link) is something you need to be aware of. The organisations who do this are those such as (1) Overpeers, __ (2) MediaSentry, __ (3) Mediadefender. This might not be the reason but is a high possibility.