A problem with USB.

[Bo-De-Gas]

I have a PC with Windows XP, with two USB ports (and two optional ones I haven't installed).
I have a Mustek 1200 USB Scanner, which Windows doesn't find unless I use it in the first port.
The problem is, I also have a 56kps modem with an USB connection, and this thing doesn't work properly unless it's installed in the, you guessed it, first USB port. When I plug it into the second port, nothing happens until I try to connect to the Internet: then my computer gets slowed down, not just the Internet but everything.
So..is my second port faulty (since two peripheral devices have problems with this?). Should I install the two extra ports (they come on a cable which I guess has to be connected directly on the motherboard).

Some specs:

OS Name Microsoft Windows XP Professional
System Manufacturer MICRO-STAR INTERNATIONAL CO., LTD
System Model MS-6330
System Type X86-based PC
Processor x86 Family 6 Model 4 Stepping 4 AuthenticAMD ~1394 Mhz
SMBIOS Version 2.2
Total Physical Memory 512,00 MB
Available Physical Memory 356,95 MB
Total Virtual Memory 1,72 GB
Available Virtual Memory 1,45 GB
Page File Space 1,22 GB

[BuBBeN]

if its a via board maybe you need tyo install the 4-1 drivers there is some usb controller in those.

[Dinerty]

Be careful with the latest 4 in 1 drivers, i installed the latest ones and it detected my CD-ROM, DVD-ROM & HDD all as SCSI, when i dont have any SCSI in my comp!.