During upgrade I am stuck in Downtime phase at RSAIMMERGE_UPG step.

HI Friends,
During upgrade I am stuck in Downtime phase at RSAIMMERGE_UPG step. Please find the logs below.

OS : Windows 2008 R2

SAp NW 7.0 SR3 to NW 7.3 upgrade

DB : MS SQL 2008 R2

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ERRORS and RETURN CODE in MRUPGAIM.BID
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A2EEAIMMERGER 003 Error when determining the tp interface version
A1EEAIMMERGER 036 RSAIMMERGE_UPG: Ended with error
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ERROR: docu input file "E:\usr\sap\BID\upg\abap\tmp\MSGIN.LST" could not be opend for read: No error
ERROR: EXIT(16) -> process ID is: 23220
### Phase RUN_RSAIMMERGE_UPG:
### Phase RUN_RSAIMMERGE_UPG:
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4 ETQ234 Call of function module "SUBST_CHECK_BATCHJOB" by RFC succeeded
4 ETQ239 Logging off from SAP system
2EETQ241 Errors found in logfiles - accumulated in file "RSAIMMRG.ELG"
1 ETQ207 Executing post-phase DB specific actions.
4 ETQ010 Date & Time: 20120330085846

#----
#---- MASKING file RSAIMMRG.ELG from E:\usr\sap\BID\upg\abap\log
#---- TIME: 20120330093458 PHASE: RUN_RSAIMMERGE_UPG
#-----

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ERRORS and RETURN CODE in MRUPGAIM.BID
~~
A2EEAIMMERGER 003 Error when determining the tp interface version
A1EEAIMMERGER 036 RSAIMMERGE_UPG: Ended with error
==

Please help.

Ravinder