VS2008/ASP.NET Randomly Changing My CSS File???

I had the strangest thing happen yesterday.

I was playing with the EnableViewState property for some table controls, ran
my Web project to the page I was working on, clicked a button that performed
a postback and refresh of the page, and suddenly all my formatting was very
messed up, for every page. Even my login page, which uses the standard login
control was higher than usual--the textboxes were taller than usual. I tried
changing back the EnableViewState property, rerunning the project,
refreshing the browser and even rebooting and it wouldn't go away.

Then, I compared my CSS file to my backup and found a couple of Width and
Height settings that were new, and wrong. I can't say that these settings
were enough to explain all the weirdness I was seeing. For example, nothing
seemed to be affecting the height of textboxes. But removing these odd
settings restored my formatting.

Did VS make some random changes to my stylesheets, or have I completely lost
it?

???

--
Jonathan Wood
SoftCircuits Programming
http://www.softcircuits.com