Uh... Let me make sure my understanding of the vaguely described "performance issue" is correct:
1) You have a license for WinBatch.
2) You are using a WinBatch script [compiled to a .EXE file? running just as a .WBT file?] to upload some files [by what method/protocol?].
3) After 2 months of working properly, now, without any changes to the installed version of WinBatch [please confirm this], and with no changes having been made to your script [please confirm this], the file upload/transfer process is suddenly taking significantly longer than usual.
If that description is accurate, I'm failing to see how what you have described qualifies as a WinBatch problem. It is highly likely that there is another element in the overall computer & network environment [including network & system resources out on the 'Net] that has been changed/modified in some way, or is otherwise experiencing a temporary problem of some sort.
Please fill in the blanks in terms of answering the above listed questions as well as explaining in more detail how you are making use of WinBatch and what the troubleshooting methodology is that you are using that makes you think this is somehow a WinBatch problem.