[Zope] fsdump.py output

I am running fsdump.py to see what is in my Data.fs file, because it seems to be growing a lot faster than it used to. The beginning of the file is a large number of object listings as expected. However, about half way through I start to see a lot of transaction information. These transactions are still in the file even though I have consistently packed the ZODB once a day. The dates on these transactions start a few moths ago, and relate to various functions in a product I have been working on. Is there something that I could have added to the code at that time (perhaps committing parts of transactions to avoid conflicts) that could be causing this transaction information to be left in the Data.fs file even after packing it?