CUDA 1.1 is not supported in Ubuntu 8.04, due to it using gcc 4.2. You either have to downgrade to Ubuntu 7.04, find an older version of gcc (might be in the repository), or use the header hack described in this thread:
Partially solved, worked with GCC 4.1. But is there a good way to specify what version of gcc to use, i updated the symlink gcc to point to 4.1, but is there a option to nvcc or an enviromental variable I can use?
Ubuntu 7.10 will be officially supported in the next CUDA release. However, Ubuntu-8.xx will not be supported in the next CUDA release, as Ubuntu-8.xx won’t be released until too late in the current CUDA development cycle.