I recently updated my Galaxy S2 OTA to the UK Vodafone variant of ICS (4.0.3). Since the update, Swype (version 18.104.22.168235) has been crashing (screen freezes, then flicks between letter and numbers, I think with the stock Samsung keyboard showing up). It was also draining the battery - using up to 60%.
I have had to switch to the (in my opinion) inferior SlideIT as it was causing me so many problems.
A few other people seem to have this problem over at XDA forums.
PS I should also add that I've factory reset the phone, cleared the cache several times etc.