JQuery :: DOM Tag Not Found When Select String Includes A Decimal Point / Fix It?

I am doing some maintenance work on a classic asp web page that displays product information. I am changing how the page looks up the available quantities for the various sizes. The old method used several SQL queries to determine the number of sizes and available quantities and then used those results to build a table on the fly on the page.

My modification consists of a web service that consolidates product size availability from three different sources and delivers the data via an XML formatted return. I have also added DOM tags in the table that is built on the fly that identify each entry with the product id and size. So, for a product that has an ID of "P12345" and a size of "XXL," that corresponding cell in the table gets an id tag of "P12345_XXL."

My jQuery update statements worked just fine using this approach until the sizes included decimal numbers. My example for this is shoe sizes. A size represented by an integer (6,7,8,...,15,16,17, etc.) works fine. A half-size represented by a decimal (6.5, 7.5, 8.5,...) does not. Even though the period is contained within a string value, jQuery doesn't seem to be able to match the value with an id tag - and yes, I have verified that the two (the string that I am giving to the jquery select and the actual tag) do indeed match.

So far, the only work-around that I have come up with is to multiply numeric sizes by 10 and parse as integer values. Is this a "known issue" and is there a more elegant solution topursue?