Compression and permissions

Ever since switching to Lion a few weeks back, we have been having various niggling problems with files and sharing such as permissions levels assigned to files unbeknownst to ourselves.

The latest, even more troubling problem involved the OS's "compression" command in the Finder. We use YouSendIt to transmit large docs to clients and have had no issues with it in the past, regardlesss of whether it was sending to Mac or Win-based clients. YouSendIt requires folders with multiple files/folders within to be compress into a single file. We don't have a third=party compresor such as StuffIt so we have been using the system-provided compression function in the File menu of the Finder. As I said we hadn't experienced a problem before but with this last attempt we encountered a glich wherein the receiving party was required to provide a password in order to exptract the files. We, of course, had none to provide them.

Now, YouSendIt can password protect a delivery but it actually charges extra in order to implement it so we KNOW it wasn't done as some mystery default setting or by accident by the person sending the file. We would have to have paid for it. Somewhere in the compression process a password was assigned to it without our knowledge.

Can someone out there give me any insights into this and preventing it in the future?