Are you using the Control Point software? Just curious as I have a M4400 with the same chipset and the Control Point software really bogged me down. I also have found that if I have used a USB port with a mouse dongle or a flash drive it doesn't want to reset. If you go into "Device Manager" and click and expand "Universal Serial Bus Controllers" then highlight each "USB Root Hub" then go to "Advanced" tab and "Reset" in lower right corner. Change to "Power Management" tab and uncheck box about turning off to save power. Do this for all "USB Root Hub" entries and see if it makes a difference. You may have to reboot after doing this, but I don't think so. Good Luck
I know it is old thread, but I wanted to answer for anyone elses benefit. No, I do not install Dell Control Bloat (but you will not have acces to some features if you don't, but it is worth it to not install) and I also do not install the Dell Wireless Card software for performance reasons. The Windows 7 driver install works far better (at least for 1510N card).
Yes, to the USB reset problem as have to perform the USB reset procedure on some new devices. My daughter has an Inspiron 1545 (w/ Vista) with ICH9 and "reset" would not work to connect to her iPod Touch. Ended up doing reinstall of OS.
I have a Inspiron 1525 with ICH9 and with the Intel ICH9 drivers installed (via F6 mode) will not connect with my USB portable hard drive, but if I let Windows 7 install the included ICH9 drivers it will connect with the drive. The Intel drivers appeared to not supply enough power (I had no way of testing this though).