安装Win7后再安装ubutu10.10，启动时，选中Windows7 后又回到Grub2 菜单

raisedragonding

我是先安装了Windows7 后再安装的Ubutu 10.10 的，安装完重启后，Grub2 启动菜单有Ubutu 启动项和Windows7 启动项，选择Ubutu 启动项能正常进入Ubutu ，但选择Windows7 时，又回到了Grub2 启动菜单。大家帮一下吧，谢谢！！
另外，有如下信息:
raisedragonking@raisedragonking-TA780G-M2:~$ sudo fdisk -l
[sudo] password for raisedragonking:

Disk /dev/sda: 320.1 GB, 320072933376 bytes
255 heads, 63 sectors/track, 38913 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x67647497

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *           1        7662    61541746    7  HPFS/NTFS
Partition 1 does not end on cylinder boundary.
/dev/sda2            7662       38913   251026039+   f  W95 Ext'd (LBA)
Partition 2 does not end on cylinder boundary.
/dev/sda5            7662       20410   102399350+   7  HPFS/NTFS
/dev/sda6           20410       33158   102400234    7  HPFS/NTFS
/dev/sda7           33158       38913    46226432   83  Linux

Disk /dev/sdb: 2041 MB, 2041577472 bytes
255 heads, 63 sectors/track, 248 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x66b1d3cf

   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1   *           1         247     1983996    6  FAT16
raisedragonking@raisedragonking-TA780G-M2:~$

raisedragonking@raisedragonking-TA780G-M2:~$ sudo update-grub2
Generating grub.cfg ...
Found linux image: /boot/vmlinuz-2.6.35-28-generic
Found initrd image: /boot/initrd.img-2.6.35-28-generic
Found linux image: /boot/vmlinuz-2.6.35-22-generic
Found initrd image: /boot/initrd.img-2.6.35-22-generic
Found memtest86+ image: /boot/memtest86+.bin
Found Windows 7 (loader) on /dev/sda1
done
raisedragonking@raisedragonking-TA780G-M2:~$