Actually, the four alphanumeric strings are identical except for all but the last digit in each sequence:
5-6-8-1
5+6=11
8=1=9
Which is consistent with the text. And serves as a "numerical suffix" for "723".
And as you pointed out, the only internally repeating sequence within the common string is "723"
If you can relate "4515 sb" to the above (4505, 4506, 4508, and 4501), then you have something . . .
The code contains the website "17tahun.com". This appears to be an Indonesian website (hello, al qaeda) with a message board. Can someone get over there and translate the posts?
Also in the code: July 17, 2003
On that day, according to the White House Press Secretary site:
"First, President Bush will welcome Palestinian Prime Minister Abbas to Washington for a meeting and working lunch on July 25th. This will be the President's first meeting with the Prime Minister in Washington. The President is committed to his vision of two states, Israel and Palestine, living side by side in peace and security, and he looks forward to discussing with Prime Minister Abbas the path forward toward realization of this vision."
Is this some sort of Hamas message?
Dear Lord, I hope it does not mean what I think it could mean.