full signal strength wrecked TiVo tuners

Hi. I have had my 2 TiVos for almost 3 years and they have worked brilliantly. Here in Australia all our tv channels have just gone digital. On most of my channels the signal strength is betwen 80 and 98. We went digital in February and we had to rescan our channels to pick all the new frequencies up. Since then the TiVos, yes both of them, won't record shows or only do partial recordings. I checked the recording history and they say not recorded because there was no signal which is crap as I can watch the tv live fine. I watch the record light come on, I check is progress and when it finishes... nothing. I have been told that the signal strength is to strong for the tv tunes and it has wrecked them. Has anyone heard of this and can it be fixed? Thanks heaps. D