Spontaneous vaporization of OSPF routes from Ascend MAX

Hi, Has anybody experienced the spontaneous disappearance of advertised OSPF routes from Ascend MAX's. The symptoms are a network routed via a radius learned profile will just up and disappear from the OSPF advertisements that the MAX is sending. We are seeing this at 5.0Ap13 and also 4.6C with some occurrences on the TNT at 1.3A. Ideas? Can anybody recommend a less broken version (there are sooooo many to choose from :( ) ? Thanks for any ideas... -Dorn