hi Harnish,
this is a wrong assumption. 001 does not clear based only on amounts.
- 001 (Standard algorithm)
Algorithm 001 interprets the values in the note to payee fields of the electronic account statement as either document numbers or reference document numbers. In the process, it checks whether the values are in the document/reference document number ranges you entered when importing the account statement. If (and only if) they are, it then tries to find the items to be cleared in the system.
Note that you must prescribe the possible intervals for documents/reference documents using the values "BELNR number range" and "XBLNR number range" in the selection screen for importing the electronic account statement.
If the reference document was stored with leading zeroes in the system, the system can find a line item only if the reference document number in the account statement is imported with these leading zeroes. If, on the account statement import selection screen, you were to enter 00100 - 00200 as the interval, the system does not find the value if the reference document number is simply 100.
check the below link for more details.
http://help.sap.com/saphelp_46c/helpdata/en/43/0bd56743de11d1896f0000e8322d00/content.htm