There was/is an issue with Canon cameras throwing an E18 error. This just means that the lens can't extend or retract correctly. Canon lumped all problems like that under a single error message and people on the net got the impression that there was an underlying flaw. All cameras with extending lenses can have this problem. Canon is very popular and lumped them all under the same error message so people leaped to the wrong conclusion. IMO, it's a non-issue, Canons are no better or worse then any other camera in this regard.
Unless you are talking about something else, in which case just ignore that.
As Doug said, the SD870 is the successor and I bought the SD800 as soon as I saw that the next version dropped the optical view finder.