I have configured Jenkins to generate builds for the GIT repository in Windows Server. My Jenkins job is configured to Poll the repository continuously and trigger build if any change is found in the repository. The issue is Jenkins job triggers automatically even there is no change in the repository. When I checked the polling log it printed the following message

Started on Oct 27, 2011 9:45:54 AM
Using strategy: Default
[poll] Last Build : #289
[poll] Last Built Revision: Revision 7fd9fb8139dd0c449a0382b505c7857c8634f33f (origin/Prod_dev)
Workspace has a .git repository, but it appears to be corrupt.
No Git repository yet, an initial checkout is required
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Changes found