Hide options in a select list using jQuery
For what it's worth, the second form (with the @) doesn't exist in jQuery 1.3. The first isn't working because you're apparently expecting variable interpolation. Try this:
$("#edit-field-service-sub-cat-value option[value=" + title + "]").hide();
Note that this will probably break in various hideous ways if title contains jQuery selector metacharacters.
You cannot do this x-browser. If I recall ie has issues. The easiest thing to do is keep a cloned copy of the select before you remove items, this allows you to easily remove and then append the missing items back.