m/b being a bit funny

[nalla]

hi all just wandering if anyone can help, ok i have a gigabyte 965p ds3 m/b recently some of my sata ports wont work so i had to use a pci sata card i had, now my usb ports are going funny, i have a lot plugged into them i have 4 at the back and 2 at the front the ones at the back seem ok i have usb mouse + epson r265 + epson r285 and a usb cable that goes to my built in hub thats in my 30" dell monitor, the 2 at the front one has an epson r1900 in and the other spare for my 360 contoller, the usb hub in monitor has 4 ports only one used for my scanner, now the whole setup works for a bit just fine the suddenly my hub in monitor stops working so i cant use scanner and my epson r1900 wont print but is recognised by the pc, when i turn off pc and back on again i can use everything again for a while then it all goes again, the other 2 printers always work fine, does this sound like my m/b is on the blink or have i just got too much plugged in, they all have there own power supply too, any help would be appreciated thanks in advance