Problem with Skip Steps

[Kerfufl]

I have a couple of steps setup like this

Group1 (build rule = %TMP_COND% is define)
Group1.1 (build rule = %TMP_COND% = "hello" is true)
Step1.1.1 [copies some files]


When the script excutes, if TMP_COND is defined everything is hunky dorry. But if TMP_COND is undefined, then Group1 runs and is set to 'Skipped' but then Group1.1 is evaluated, and prompts for the value of TMP_COND. It shouldn't be evaluating the condtion for a step that should be skipped because it's parent build rule evaluated to false, right?

Anyone seen this too? I'm using 5.5 is the problem fixed in 5.7 ?