I am having similar issue with RC, where I am not able to connect to the Internet after installing Adobe Photoshop CS3. I have uninstalled photoshop and it started working. I have used photoshop without any issues with Win 7 beta though.
I am having a strange problem. I googled it and saw couple of people with similar issues, but no resolution. My Internet stopped working after I installed Photoshop CS3. Network is active and I can connect to my network computers but not to internet. This happens only when you reboot after CS3...