Lg Viewty Ku990 can't connect to either PC suite or mass storage

I've always had problems using the PC suite, sometimes it would work, sometime not. So I got a memory card and changed is from data service to mass storage and I could add music straight from Windows Media Player. But recently when I connect my phone via usb my computer beeps so it knows it is there but if I go into computer to find mobile folder- it is not there and if I use PC Suite it will connect for a few seconds and then disconnect for no reason. It is really frustrating and everything about the phone is great- apart from the usb music and I only really use phones for music :P, i'm considering going back to sony ericssons if I cannot get a solution, i've scanned through all of the forums and done many methods but nothing seems to be working. I hope someone can hel. Thank you in advance, Matthew