My device keeps dropping its USB debugging ability

Hello everyone. New here but not to development.

I have a very frustrating problem that I'm sure others out there must have experienced. Some details first:

• I am running Windows 7, using Eclipse ADT.
• I have SAMSUNG_USB_Driver_for_Mobile_Phones_v1.5.33.0 installed.
• I am using a Samsung Galaxy S4 to develop with.
• USB debugging is set to on.

So what happens is this:
I am able to develop/run/debug normally through Eclipse and it sees my device no problem. Each time I connect my device to the computer the device says, "Connected as media device", Windows 7 gives a little sound and I can debug/run my programs after that.

However every so often my computer refuses to see my device as a media device and it can only recharge, it can't be seen by Eclipse ADT and it isn't seen on my Window Explorer. It will only charge. This happens even when the battery is at 90% or higher.

I tackled this problem the other day - uninstalling the drivers, reinstalling the drivers, installing Kies (and Kies 3), uninstalling Kies (and Kies 3)... rebooting, rebooting the device...I just kept trying these things until suddenly Windows would give me the happy 'connected' sound and could see it as a media device (thus allowing Eclipse to see it as well).

I thought I had the problem solved and it has been working fine the past couple days, but now again, out of the blue, Windows refuses to see my Samsung (or Samsung isn't communicating properly) and I can't develop as Eclipse can't see the device either.

Has anyone else experienced this? If so can they tell me what's going on and how can I prevent this? It's very frustrating when all you want to do is work and you spend the whole day trying to force the devices to see each other.

Thanks in advance.
Peter