HELP! Google Safe Browsing Stopping Website Viewing

I have a OSC site which is giving a Google Safe Browsing Error: What is the current listing status for MY WEBSITE? Site is listed as suspicious - visiting this web site may harm your computer. Part of this site was listed for suspicious activity 1 time(s) over the past 90 days. What happened when Google visited this site? Of the 1 pages we tested on the site over the past 90 days, 1 page(s) resulted in malicious software being downloaded and installed without user consent. The last time Google visited this site was on 2010-09-24, and the last time suspicious content was found on this site was on 2010-09-24. Malicious software includes 1 exploit(s). Successful infection resulted in an average of 1 new process(es) on the target machine. Malicious software is hosted on 1 domain(s), including xxxxxx. This site was hosted on 1 network(s) including AS8560 (SCHLUND). Has this site acted as an intermediary resulting in further distribution of malware? Over the past 90 days, MY WEBSITE did not appear to function as an intermediary for the infection of any sites. Has this site hosted malware? No, this site has not hosted malicious software over the past 90 days. How did this happen? In some cases, third parties can add malicious code to legitimate sites, which would cause us to show the warning message. I hope someone is online now that can help me as I am losing sales! Lowest bid will secure work.