I forget which little hack this is associated with, but I have found that, on my host, this particular file - parse_time_log has ballooned to 937Mb.... I overwrote this with a zero-byte empty text file and everything seems fine.....
Has anyone else experienced this?
Also, I noticed that when I overwrote the file - permissions of 755 resulted in nothing getting written to the file, but when I changed this to 777, it jumped from 0k to 10k in one refresh of a page...