Will not connect via USB hub - SanDisk Sansa e250 MP3 Player

is usb hub powered or passive ?
had trouble with usb hard drives on usb hybs - research on solution is a powered hub .
Not sure if this is issue for your problem

If the Mouse USB receiver is connected to the computer via a USB Hub, disconnect the receiver and plug it in the computer directly. Hubs interfere with mouse wheel signals.

Sir/Madam

1. Is the printer turned on?
Make sure the printer is turned on.
Make sure the power cord is securely plugged into the electrical outlet.
Test the power by plugging in the power cord of another electrical appliance to an electrical outlet and turn it on. If the power to the other electrical appliance comes on, the printer may be considered to be faulty.
If this product is recognized:
Close this page to return to the installation window.
If this product is not recognized:
Proceed to the next step.
2. Are your computer and the printer correctly connected?
Make sure the USB cable is securely connected to the printer and to your computer and check that the USB cable is not damaged nor badly crimped.
The printer will not be recognized during the driver installation if connected to a printer switch or the printer buffer. If this is the case, try to directly connect the printer to your computer using the USB cable.
If you are connecting the printer to your computer via a USB hub, connect the printer to the first-tier hub from your computer. If the printer driver is still not recognized on your computer, try to directly connect the printer to your computer without the USB hub.
If you are connecting the printer to your computer via a USB hub, make sure the USB hub device is recognized by your computer.
If this product is recognized:
Close this page to return to the installation window.
If this product is not recognized:
Proceed to the next step.
3. Does your computer provide USB or IEEE 1394 support?

If Still Your Problem Is not solved Then Click On Below URL
http://files.support.epson.com/htmldocs/r1800_/r1800_rf/dset_1.htm

Or

Still You have problem Then please Follow Us On HP Printer Support

yes, you can. I have my printer connect to my hub and my desktop and I can print from my laptop wirelessly.
You will need your all in one connected via a printer or USB cable to a computer AND also connected to your hub. Then, go to the computer that is connected through a cable to the all in one. Your all in one should have some way to configure its IP address. I have my printer configured as 192.168.1.4 and it's plugged into the 4th port of my hub. Check if this works.

The problem is the USB hub, this often leads to a proper signal routing, as it splits the signals to smaller data packets. Remove the hub and all other USB ports. Let then newly recognize the PC your USB connection (not via Hub!).

it shows the hub issue, if hub is ok (try it to other system) then the acer did not support such hub to power up.

I had similar problem recently. I noticed that I had forgotten to connect the power supply cable to the USB hub, to which my FreeAgent Go was connected to, after I had connected all my USB devices to my computer's USB ports (after I had disconnected everything from my computer in order to isolate another issue). Reconnecting the power supply cable immediately stopped the flashing light and windows recognized the drive.

Don't know how you are connecting yours to the computer i.e. via a USB hub or directly to the computer's USB port. Note that my FreeAgent Go drive requires both USB connectors connected to the computer (or to USB hub). Two USB connectors are on one end and the other end of the cable is connected to the drive/docking station.

Hope this helps.

Some motherboard BIOS's allow you to specify how many USB ports you want enabled
go to your Control Panel, System, Device Manager.

go down to where it says Universal Serial Bus Controllers, click the + sign,
you will see a list of devices, probably something like this
via rev5 usb host controller
via rev5 usb host controller
usb printing support
usb mass storage controller
usb root hub
usb root hub

right click on the ones that say via or intel or SIS, or ALI, or Standard open host controller, and choose uninstall.

you will be asked if your sure, and you will see some of the USB root hubs disappear.

If you are asked to restart, choose no, and remove the other via/sis/intel/etc open host controller (s) from your system, when they have all been removed restart your computer.

when the computer restarts, it will detect the USB controller and connected devices, reinstall the drivers/software

Airport Express provides only a print server, not a networked usb hub so it can only print. I'm afraid you'll have to go back to wired for scanning.

Use of a USB hub for connection does not guarantee normal operation. Try attaching the USB cable directly from the D-snap SD Camera to one of the built-in USB ports on the PC.