2.5" USB Enclosure Issues

Hi im a bit new to these forums.

I have an issue which is really bugging me, so I bought two 2.5" USB + eSATA Enclosures from ebay, and i fitted two hard drives that work fine.

When I connect the enclosure to the computer with the USB cable to the Front and Back USB ports, the enclosure starts beeping continuously. But when I connected it to my Monitor's USB ports it worked fine, and even when I connected it to my dad's pc it also worked just fine.

The USB cable comes with 2 usb's, I tried to connect them both and still I heard beeping when connected to front and back usb ports. When connected to the monitor only one USB is used, and it works.

One's a seagate the other is Fujitsu. But they work fine if you remove them from the enclosure...

And how do I do that dwarf? coz I bought them from eBay, all I know that they're branded SUMVISION

Egem Combo 2.5" Sata to Esata/USB HDD Enclosure I did find this on the website of sumvision.
OK on my box there is written SV-140. Is that good enough for you guys?

well yeah but all it says how to install a hard disk drive into the enclosure.

yeah and I even tried connecting it to my dad's pc and it worked flawlessly.. So makes me wonder if there is something wrong with my front/back ports but the thing is when I connect an other USB drive into the front/back ports that device works fine.