Hi frank
My saw is out of commission from the past 3 weeks PROXXON for the very same reason( the threads are worn out on the rod) since it is under warranty the part is being replaced by the distributor on the way from Germany. I think I agree with Jscott2 that maybe I was over tightening the tension on the blade.
If your saw is not under warranty what I can suggest that you get that part made it is a steel rod,you have the thickness ,length and the type of thread,I think any machining shop will be able to do it.I am not an expert in this area but it just hit me that it can be done! I am sure our friends on the forum will be able to help you out with some other suggestions and ideas.
When I get that part I am going to get it duplicated just incase I have the same problem again as the warranty expires next month
Hope I was able to contribute some solution.
Mahendra