Hi I have a very strange problem with my links every first time someone visits my website. It looks like this. After I reload the page, the links are correct.

www.xxxx.nl/?967013821739191d0a9601d9757...c8841c7e3f76750cc3f4

I would really like to solve this!!!

This looks quite strange - it appears like some md5 hashes.
You don't give much information, but nevertheless I do not see any connection to JoomSEF and have no idea how JoomSEF could be causing this.
More lilkely, this is caused by some other component or some JavaScript or other piece of code at your site.