Insurance quotes and credit inquiries

Recently I requested a car insurance quote from GEICO just to see how competitive their rates were. As it turned out, my current insurer, State Farm, has a much better rate for me. I have two speeding tickets in the last 5 years but my monthly insurance is still very reasonable. I have been with them for 17 years so that may be a factor. Anyway, this morning I received an email from GEICO telling me that my rate quote may have been higher due to my credit score. Below is an excerpt of the email. I checked my score in August and it was about 750.
”Since we may have been able to offer you a lower rate had the report been more favorable, we treat our decision as an adverse action under the Fair Credit Reporting Act. You have the right to obtain a free copy of a consumer report from the reporting agency listed above, provided your request is made within 60 days of receiving this notice.
The specific information provided by Trans Union that may have influenced our decision is:
-Insufficient length of credit history (-)-Too many recent credit checks (-)”
Apparently this type of credit check is a “soft” credit check and it will not effect my credit score. My recent credit checks includes applying for a refinance mortgage in October 2006, applying for a Discover card to take advantage of a 0% offer in January 2007, and accidentally hitting the “Bill Me Later” logo and not realizing what that entailed in August 2007. How many inquiries in a 12 month period are considered to be okay?