tested with version 6.03
issue the following command in a script:
ignore -u $+ $1 $2 8 $chan
it generates the following response from mIRC:
* Updated ignore switches for test_nick!*test@*.dsl.lsan03.pachebel.net
but when I check the ignore list it shows:
test_nick!*test@*.dsl.lsan03.pachebel.net (pcntdik) <channel-name>
in other words, the "remove after n seconds" flag is not set.
When this was discussed some time back, the ignore hadn't taken effect because a query window was open -- in my testing only a channel window was open.
Also, I've tried this with timeout values 10, 30, and 60 seconds, all with the same result.