End to the Noob Bashing...
Just realised that i was looking at the wrong post when i posted this data so the reasons for posting bit at the top of this will make no sense....sentiment still true though. Hope it helps either way.
Ok, i'm a Techie. I know without a shaddow of a doubt that my Laptop is fine in every respect and yet it was doing this to me also.
Believe me when i say, you're not insane, and despite what others say you DO have a valid question which DOES deserves a valid answer...ENOUGH of the trollish Noob bashing 'non answers'.
If you are having the EXACT same issue as the original poster, heres what you do:
With your phone unplugged....
Make sure you have updated Kies to the most recent version. Either do this by going to your mobile phone opperators website and downloading the updated software version directly or by using the help --> Check for Updates option. Latest version at time of writing is: 18.104.22.16871_128.
Once up-to-date, close Kies. Although probably not essential, use 'Task Manager' to end any Kies related processes.
Uninstall Samsung USB Driver Software:
1) Navigate to Control Panel and open either (Windows 7/Vista) 'Programs and Features' or (Windows XP/2000) 'Add Remove Programs'
2) Scroll through the list of programs to find one called 'SAMSUNG USB Driver for Mobile Phones'. If it is installed, right click it and select 'Uninstall'
3) Run through the process of uninstalling the software.
Tidy up Devices:
1) Right Click 'My Computer' select properties
2) On windows 7 (possibly Vista also...dont know as I skipped that generation) ONLY, select the 'Advance System Settings' option over to the left of the window.
3) Select the 'Advance' tab in the 'System Properties' window that appears.
4) Click 'Environmental variables'
5) In the 'System Variables' section of the window that appears, click 'New...'
6) In 'Variable Name:' type 'DEVMGR_SHOW_NONPRESENT_DEVICES' without the quotes
7) In 'Variable Value:' type '1' without the quotes
8) Click 'OK' times 3 to exit the windows you opened
9) If Windows 7 (or Vista) close the 'View basic information about your computer' window also.
10) Open 'Control Panel' and navigate through to 'Device Manager'
11) Click the 'View' menu and select 'Show Hidden Devices'. This will display all mothballed devices i.e. those devices which have previously been plugged in but then removed. Windows stores a record of the drivers in the background of the system to speed up the process of installing the device drivers when you next plug in said device. Sometimes, in the case of Network Cards for example, not only will it store the drivers but it will also store its settings. This can cause a problem as if you were to plug in a replacement Network Card and set it to use the same static IP address, the mothballed device will clash with the current device. Without the environmental variable setting being configured as above, even when you show hidden devices, mothballed devices remain hidden.
12) Starting from the top, expand each of the branches in the tree to see the devices within them.
13) Look for anything with a 'Samsung', 'MTP', 'GT-I9000' prefix. If found, right click and select 'Uninstall' and confirm at the prompt. BE CAREFUL NOT TO UNINSTALL ANYTHING YOU ARE UNSURE ABOUT. Google it if need be to figgure out what it is and if its not a Samsung or android related device then leave it well alone.
14) Close Device Manager once you have assessed the final branch.
Re-Install Samsung USB Driver Software:
1) Open Kies
2) Expand the 'Tools' menu and select the 'Install Driver' option.
3) Click ok to any prompts to fire off the process.
4) Wait for it to complete.
5) On completion click 'Ok' to acknowledge if required.
At this stage, it may be worth turning off your Windows Firewall and AV scanners just to be on the safe side. Probably not an essential step but may make a difference. If you're not confident enough with computers to do this then dont bother.
Re-Connect Samsung Galaxy Device:
1) Plug the Micro USB cable that came with your device in to ANY
of your most trust worthy USB sockets.
2) Plug the other end into the Micro USB socket of your Samsung Galaxy S.
3) Allow Kies to pickup your device and display the storage information proving it is properly connected.
4) If an update is avaialble for your device, Kies should prompt you. If you are confident that you have all the data backed up onto your computer, then proceed with the Firmware update.
5) Click either the Backup or Skip Backup option.
6) Panic a little when the device appears to disconnect YET AGAIN!
7) Chuckle to yourself knowingly once it blasts through this onto the update.
8) Once completed unplug from and re-plug your Samsung into your computer again.
9) Upload your backed up data.
10) Get rid of the God-Awful default dasktop layout that your Mobile provider forces onto you.
Dont know what causes this but what i have noticed is that once you have tidied the mothballed system devices related to your phone and re-installed the device drivers again, it appears as if there isn't any devices named with the prefix of 'MTP' in the device list but there are a few more labelled with a 'Samsung' prefix.
I suspect this is something to do with Samsung at long last fully qualifying their own drivers but not bothering to tidy up the mess that the old devices left behind as part of the Kies update process. Either that or Windows prevents the Samsung USB Driver installer software from being able to delete/update existing Samsung devices.