This is why I'm somewhere in the middle in the whole debate. I think certain reactions to the vaccines are not very common (or we would see a lot more cases than we do), but I also don't like when I see concerned parents being ridiculed for being "anti-science." It actually seems rather scientific to me, to look to that event as a possible cause if nothing else happened during that time, especially when it isn't so easy to prove either way. If it were easy, in all those reported cases, doctors would have been able to point to exactly what DID cause it.
On the Merck website, I found this (from the MMR package insert):
"Experience...indicates that significant central nervous system reactions such as encephalitis and encephalopathy, occurring within 30 days after vaccination, have been temporally associated with measles vaccine very rarely. In no case has it been shown that reactions were actually caused by vaccine...However, the data suggest the possibility that some of these cases may have been caused by measles vaccines."
In other words, they are admitting that although not PROVED, it is POSSIBLE. And again, I completely understand that those cases may be rare which is why I don't consider myself anti-vaccine, but I also don't like to see people hiding behind science, when science itself doesn't always have all the answers. It is OK to be suspicious.