Copy part of file between two strings to another

I am a newbie to shell scripting
I have a large log file , i need to work on the part of the log file for a particular date.

Is there a way to find the first occurance of the date string and last occurance of the next day date date string and move this section to a new file.

to explain it further.
There is a file like this
-------------------
10/30/2012 some old data
10/31/2012 some data
some other lines without date
10/31/2012 some more data
11/01/2012 some other data
----------------------------

I need to find a way that will return only the lines 2,3,4

So i was trying to find , if there is a way to find the section between the 1 st occurrance of 10/31/2012 and 1st occurrnace of 11/01/2012

I will also need a find a way to find the section between 11/01/2012 and end of file.

sed -n '/10\/31\/2012/,/10\/31\/2012/p' file

sed -n '/11\/01\/2012/,/$/p' file

I am getting the following error on sed command
This generating the following error

[2012-11-01 02:08:39,943 | ERROR | WebContainer : 3 | | MRF - Report UI] Print Requestor is not setup for user =B05SQMplease setup it.

Can anyone tell what it the resolution for this

It s working for a different user