Ttile with over 38 characters become twice the size

Simple h2 tag with a class of pageTitle which is defined at 20px in CSS.

All my titles look great UNLESS they are over 38 characters including spaces then the font size doubles!

Any idea why this would be, I have isolated this to the cause by creating very simple test with only the most basic code and when I am at 38 or less it is great if I increase the size it doubles, if change the title to something 38 or less it returns to normal. This is critical as I cannot have this limitation.

Thanks for any help with this.