Bukkit

    - '// First of all, we need a clean object for the test'
    - '@DELOBJ $TestObj'
    - '// Now create the variables'
    - '@SETSTR $TestObj.Str1 Str1!'
    - '@SETSTR $TestObj.Str2 Str2!'
    - '@SETSTR $TestObj.Str3 Str3!'
    - '@SETINT $TestObj.Val1 500'
    - '// Debug'
    - '@PLAYER $TestObj.Str1'
    - '@PLAYER $TestObj.Str2'
    - '@PLAYER $TestObj.Str3'
    - '@PLAYER $TestObj.Val1'
    - '// Error happens when i remove the last (or unique INT)'
    - '// It wipes the other variables too. I didnt try the inverse'
    - '@DELVAR i $TestObj.Val1'
    - '// Final Debug'
    - '@PLAYER $TestObj.Str1'
    - '@PLAYER $TestObj.Str2'
    - '@PLAYER $TestObj.Str3'
    - '@PLAYER $TestObj.Val1'

i use VariableTriggers v1.3.3 (or 1.3.3.1)

I recommend using the same data type for all of them, I'm not sure as to what the problem is at the moment, but I'll put it on my list to look at.