Personally, I'd stick the the method Dognatch suggested. It's much cleaner, imo.
As for the problem with it failing, it would help if you (OP) can paste about 10 lines or so around the one you think is bad -- starting about 5 lines before and going to about 5 lines after. That will let us see what's going on around it in case there is something messed up nearby and it really isn't the line you think it is.
