Mia'cova, I'd love to hear more about your failures to connect directly when sending a file to someone on the same network. That really shouldn't happen and it's something we are quite motivated to fix (If you're sending the file through our servers, it's costing us money. If you're sending it over your ethernet, it's not.)
You can turn on a connectivity log under tools|options|connection|advanced that will contain a fair bit of the information I'd need to see what's up. If you could get the logs for both your machine and your buddy's machine I can have someone on my team take a look. Heck, add me to your buddy list, set up a shared folder, and put the files in there. I'll look at them when I see the gleam.