I was working on a SSRS project where I was using multivalued parameters. This creates a drop down list whereby the user can select the relevant values. Unfortunately in SSRS 2005 (SP3) the width of the dropdown is fixed, which seems to me as a bit of an oversight.
I believe that this may be corrected by altering the HtmlViewer.CSS file or by programmatically fixing the width of the available parameter values.
Neither is ideal.
I will look into whether this has been rectified in SSRS 2008.