Yes, several, one I actually filed.
Solutions?
- Avoid choke points such as beacons or ILS approaches
- Listen at-least to nearby LARS controllers
- Bloody good lookout
- Squawk, with ALT
- Bloody good lookout
I'm personally unimpressed about the common advice not to fly at standard round-number altitudes, it's pretty much irrelevant as most PPLs don't fly height very accurately anyhow. On the other hand, consider on longer trips asking for clearances and flying in controlled airspace, where the risks are rather less.
If you can find a current or retired fighter pilot, ask them how they do lookout - it's almost certain to be a better method than used in most GA.
G