Reporting Services Date Format Problem

I have a huge problem with reporting services..

For any reports I am running it interprets all of my dates as US format.

for instance I'm using the following code snippet to specify the date range of a report

CAST(@FromYear + '-01-' + @FromMonth AS DATETIME) AS froom MIN(allpartmaster.snlcat) AS cat, DATEADD(dd, - 1, DATEADD(mm, 1, CAST(@ToYear + '-01-' + @ToMonth AS DATETIME))) AS toooo

these are then used to not only limit the sql statement's return set but also as labels on the report for clairfication.

parameters are of string type but are passed the likes of

@FromMonth = '06'


@FromYear = '2006'

@ToMonth = '03'


@ToYear = '2007'


Now I run the report on my developemtn machine with out any problems the above returns


froom = '01/06/2006' the 1st of june 2006
toooo = '31/03/2007' the 31st of March 2006

now when the report is deployed and run on the server the above returns

froom = '06/01/2006' 6th of January 2006
toooo = '02/02/2007' 2nd of Feb 2007

so the dates are being displayed in the correct format for what they are.. but the actual processing of the reports on the report server is flipping them to US format initially and then back to UK format to display them.

I'm at a loss to understand why.. my browser's language settings are UK and my server's windows regional settings at UK as well...

does anyone have any ideas as to why this is happening?