Conflicting with equalHeights module

Hello.

I am building a theme(one-sidebar and content) with Zen StarterKit and I have the following situation:
When equalHeights is enabled on class column(a.k.a: making left sidebar and content the same height), in pages where the sidebar is bigger(in height) than the content, the left sidebar is stretched above from calendar block. What I mean is that instead of getting the content large enough to get equal height with sidebar, the sidebar is moving simultaneously up with content moving down and they reach each other exactly above calendar block leaving it "on the air".
If I try any other block there is not such a problem since the sidebar doesn't change height.

What I see from firebug is that the calendar block module is overwritting(disabling) the following CSS rules:

overflow: vissible
height: 200%

which are applied in .region-sidebar-first div in my theme's stylesheet.
If I add !important next to height: 200% the sidebar becomes tall enough to include calendar block (but the content doesn't come up with - that's where the equal heights module is also involved).

I didn't know where to post this issue on equal Heights module or here so I choosed here because of the CSS overwritting by the calendar block module.

I am sorry I know it sounds complicated but I couldn't make it simpler