I'm trying to think of how this situation works. And the only one I could come up with is that you're writing software that your clients use internally. Or I guess the software could produce something that your clients would end up selling to their clients.
The biggest "risk" is where you interpret the user of the software. At what level does the rights to view, modify and redistribute go away? Does your client have to make source available to its clients?
This is one of the holes closed by Affero version of the GPL. Where internal GPL code is used as a server and uses a documented non-GPL protocol and is not distributed.
The biggest "risk" is where you interpret the user of the software. At what level does the rights to view, modify and redistribute go away? Does your client have to make source available to its clients?