I am unable to connect my samsung mobile as mass storage devic

Which is mobile phone OS ?
Could you run command "sudo lsusb" to check that phone is seen on USB bus.

1. lsusb output is:
Bus 006 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 005 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 003 Device 002: ID 03f0:171d Hewlett-Packard Wireless (Bluetooth + WLAN) Interface [Integrated Module]
Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 002 Device 002: ID 04e8:f000 Samsung Electronics Co., Ltd
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root
2. Its java phone

I googled on "04e8:f000" but find nothing clear. You can also request help on http://ubuntuforums.org/.
Samsung SCH-U290 (Bus 004 Device 002: ID 04e8:f000 Samsung Electronics Co., Ltd )
http://kubuntuforums.net/forums/index.php?topic=3116287.0;wap2 also had an issue when he went to 10.10.

As USB mass storage protocol is a standard one, it looks strange.
Do you see the phone in /media folder ?
Did you made an update of system after 10.10 ?
Could you try on a live session of 11.04 to see if issue still exist.

How about transferring files through Bluetooth?

yes, but data transfer is slow via bluetooth

thanks to all
the problem is solved using following
sudo gedit /etc/usb_modeswitch.conf
DisableSwitching=1

thnx

The same issue exists in Ubuntu 13.04 too.
The solution works. Thanks!!!

Thanks
The solution also works in Ubuntu 12.04.