proxy data corruption?

I was wondering if anyone had this similar problem:

I'm using Ghost Surf 2005, but when I check email, only parts of the page loads (sometimes it also just shows jibberish). So I have to reload it a a few times to show the all the buttons. Also, when sending attachments sometimes the can't be opened by the recipient. I've noticed that when I download attachments, even pictures, sometimes only part of it is downloaded or opened. For example, I view a web page with some pictures, if its a large picture, only the top 20% shows up. If I recieve a document or pdf in email, its a few kb smaller than what the email says it is (then it can't open either).

This doesn't always happen, but sporadically so... Is this a problem with the proxy? I've tried a few other public proxies and sometimes this also happened... How to avoid this? Any Ideas as to why this happens?