Sometimes the wireless connection is disconnected and turned off the computer must do to correct it.
A full update was done to try and fix this, and I searched many forums for this problem but i found nothing.
Here is my wireless information:
[0280]: Intel Corporation Centrino Advanced-N 6200 [8086:422c] (rev 35)
There is a very good step by step wifi support section on the Ubuntu site at
https://help.ubuntu.com/11.04/ubuntu-help/net-wireless-troubleshooting.html
Work carefully through this site following the instructions in order. This can fix many problems. You might want to do this with a wired connection available in case things go wrong.
Once you have done this very carefully see if the problem is solved.
If you problem has not been solved after working through this you can do the following that might help (it does for me on my netbook). Connect to the wired connection. Go to the software section and install WICD. Go to system settings-startup applications and add WICD as a start up. Uninstall network manager (this is very important). Reboot and see if this helps.
I have a Latitude e6510 (same wireless hardware) running Ubuntu 11.04 and my wireless works flawlessly.
I know this series of laptops has a hardware switch along the right side to kill any wireless connections. Are you sure you aren't accidentally flipping that switch? The next time this happens try toggling the switch, does that fix the connection?