"invalid date" - (2000i)

["jim f." <bigbubber@xxxxxxxxx>]

often, when i adjust the time frame (or whatever) on a symbol, i receive the
"invalid date" error. seems random. i have 3 machines set up w/ ts 2000i and
have received it on all
at one time or another. i've looked all thru my settings for date. is it a
known bug?
another n00b mistake?
closing TS, then restarting corrects the issue..

thanks, as always
jim