No good reason to "Send to compressor". It's the slowest exporting method. Your best bet is to create the desired preset in Compressor and then add it to your "Shared destination" in FCP X. You can then export from FCP X directly.
If it doesn't, the culprit should be somewhere in /YourUser/Library/Application Support/Compressor. You can delete everything in that folder and empty your trash (all settings and destinations will be lost).