When you switch your E-80 on and press either the Style or the User Program button and then choose "External" (meaning the memory card) the operative system starts transferring the files from the "Put new Styles/UPGs here" folder to the "Styles" or "User Programs" folder. Sometimes this process gets halted because a style or a UPG has a "wrong" name (one with characters the operative system does not accept) or is corrupted (this is true especially with styles).
So my advice is to try to load them little by little, adding maybe 20-30 styles or UPGS at a time to the "Put new... here" folder and then seeing if they are transferred to the destination folder. The moment this process stops you will know that one of the files is invalid or corrupted: if you can find it and remove it, your problem will be solved.