Playback and transfer issues - Sansa Clip+ Rockbox 3.13

[M462]

Hi ! 

Almost 3 months ago I started having issues while playing music (mp3), songs mixed with the start of other randomly or the player freezes and I have to press the power/off button for 10 seconds to turn it off.

Besides I can't transfer data. Device manager shows me an wpd filesystem volume error. I found other people that solve that issue by changing the letter of the unit, but, It doesn't work for me, tries to connect but disconnects quickly, by the way I don't use external storage, just internal (always).
http://goo.gl/6ISO1W
http://goo.gl/Z53Thv

Once, it connected as external storage, but when I opened it showed me a lot of files with weird characters. I uninstalled Rockbox and then installed it again but nothing (through original Sansa firmware).
http://goo.gl/R8U82X
http://goo.gl/ad0nFC

I thought it was a process on my PC or something so I attempted to put it in other PC with WinXP (x86) and it doesn't work neither. So plan B was start the player with original Sansa firmware and then connect it, that works with no problems for transfer.

Some ideas about the USB problem or the playback issues?.

Thanks for your time :3

Windows 7 Ultimate Spanish (x86)
Sansa clip+ (4gb)
Rockbox 3.13

[saratoga]

USB is buggy on some systems. If it doesn't work use the Sandisk firmware.

[M462]

Yeah that's what I did all this time :c
Well, nothing else to do, I'm gonna wait a fix for both issues...
At least original firmware keeps working for transfer xd
Thanks