iMac 27" airport not connecting

When the lion osx became available I downloaded it on the iMac and now I'm finding that as frequent as every second time I turn on the machine the airport hardware is not installed....... Obviously it is installed and when I restart it is fine........anyone experienced this? Hopefully there is a patch or a fix for this.

Slightly of topic but how good is lion by the way. Trackpad for the iMac is by far the best thing I ever did love it