Release numbers ending in 0

The latest version of my game Gigalomania is 0.20, but when I try to create the milestone/release, Launchpad strips it to 0.2: https://launchpad.net/gigalomania/trunk/0.2 .

A fairly standard practice for version numbers is that they are not real numbers, but rather, lists of integers separated by dots. So I am following minor.major; 0.20 is the 20th release of the 0.x series, not the second. Another obvious example would be any release that uses multiple dots - e.g., a program released as 1.0.9 clearly isn't a real number, and as such there is no reason why a minor update shouldn't be 1.0.10, rather than having to be 1.1.0. As some common examples, the version of Windows I'm using is 6.1.7600; the version of Opera is 11.50. Ubuntu also follows a format of x.04 followed by x.10 - surprising that Launchpad doesn't seem to recognise this. I see that Ubuntu instead uses the names for the releases on Launchpad, so perhaps a workaround is to use a string, but I'd rather use the straight version number.

Is there a way to get Launchpad to recognise my release as 0.20, or is this a bug?

It's not a huge problem for me for now - I can simply write in the comments that it's meant to be 0.20. I wasn't using Launchpad at version 0.2, but this is a potential problem in future - e.g., if I want to release 1.10, and I'm already using 1.1.

Thanks.