SharePoint Content Source Crawl Error

[Kelly]

I have created a SharePoint File Shares Content Source. When I run a crawl on
this Content Source I get multiple errors of “Access is denied. (The item was
deleted because it was either not found or the crawler was denied access to
it.)”, of which the majority appear centered around TIF files. So I copied
all the TIF files to a separate directory and had SharePoint crawl that
directory 5 times. Each time it came up with different results:

109 Items: 36 Successes, 73 Errors, 0 Warnings
109 Items: 29 Successes, 80 Errors, 0 Warnings
109 Items: 26 Successes, 83 Errors, 0 Warnings
109 Items: 17 Successes, 92 Errors, 0 Warnings
109 Items: 25 Successes, 84 Errors, 0 Warnings

So I deleted all but 2 of the TIF files and ran the crawl again and
everything was fine. Does anybody know why the results would change like this?

Is there something I need to do to get more success with crawling these
files or is there a more detailed log that tells me exactly what the problem
is?

Thanks.