Qimage will never change settings if all you do is change the profile.  It only changes settings when you do one of two things: change the printer or the media type.  Very old versions used to recall settings when you changed profiles but I took that out years ago: for the same reasons you mention.

So if all you did was drop down "Printer Profile" and change the profile, it will never change settings based on that change!  Most likely what happened was that you changed the media type from one type of paper to a different one: in that case, it'll load the last settings used for the new media type you selected.  If you don't want that, simply remember to change your media type first and then make your driver (or other) changes and then save that setup under a user specified name.  The only time that typically happens is if you have, for example, two types of matte paper that use the same matte media type in the driver: maybe one for Canon Matte and one for Red River Matte.  The only time you should ever run into trouble is if you are currently on a media type such as Canon Glossy and then you start to make changes from the bottom up: like you change the ICC profile first, then some driver settings, and THEN you change the media type from Canon Glossy to Canon Matte at which point it'll recall the last settings you used for the Canon Matte.

Bottom line: don't do things backwards.  Always start from the top and select your printer and media type first.  Then you will never have a change of settings overwrite what you are doing.  And if you have some paper types that you use frequently, even if you did go backwards (bottom up) and ran into a problem you should only run into a problem once: when you get your settings set up the way you want, save them as a printer setup and name them!  That way when you want to use Red River matte, you load your saved "Red River Matte" setup and when you want to use Canon Matte, you load your "Canon Matte" setup.  Qimage is the only program that allows you to save setups so you shouldn't be changing settings regularly anyway.  You should be loading saved setups that have already been previously prepared.

Regards,
Mike