Software problems with measurements

Hi,

I do not know what is happening but suddently I am unable to use properly CorelDRAW X4 due to measuremets issues.

I have a simple document I wish to work on with size 20,45cm x 15,40cm

I first create a new empty file (A4). Then I click on the empty working area and select on the toobar the measure of the area (where I already find 210 cm and 297 cm). I try to change the measure from 210 to 180 (as example) and after I type 180 and press enter the value changes to 1,800 cm and the working area becomes very very big.

It seems anything I do I am unable to obtain what I need.

I do not understand the behavior of this software and do not know what to do.
I tired to delete Corel user profile but nothing has changed.
The software has always worked properly. My OS is Windows 7 Pro x64.

Please help.

Thank you