Yes, it's unclear what you mean when you say "I'm still getting blown highlights."
But I will guess that you mean the highlights "look" blown out on you monitor, even though Photoshop measures their values at something less than 255. If that's true, I suspect you have your monitor brightness set way too high.
When you calibrate a monitor, brightness is one of the variables. Usually measured in "CD2" values. People argue forever about what the CD2 brightness value should be. The normal accepted range is 90 to 120. Some monitors, especially uncalibrated monitors are set much higher than that by default. The higher you go, the more likely that highlights in the 230 to 250 range are going to "look" blown out.
So, check you monitor brightness. Your calibrator should tell you what it is. Or, you can use this slick trick with a camera:
http://www.hermitage-ps.co.uk/monitor_luminance.htmPlus, there are many web sites that help you check your monitor. Here's one:
http://www.wpdfd.com/issues/28/optimising_your_monitor_for_web_design_2/As for PhotoBucket, I don't use it but I'd be surprised if it's adjusting your saturation. More likely that you are confusing it with colorspaces. Are you uploading to PhotoBucket with jpegs in the sRGB colorspace? If not... if you are uploading jpegs in Adobe98 or ProPhoto colorspace, huge shifts in color might appear.