Computer prevents marriage

[Vomaxx]

I killed James; I killed the Kraken; I spoke (not for the first time) to Mirabella and told her James and the Kraken were dead; the game crashed. (Three times so far). Something called DEP told me the "problem event" was a "BEX" error. Any suggestions? I will try to fix this on my own, but I am something of an ignoramus about computers, so I will be fumbling around; I thought I'd post here, too. (Anyone kind enough to suggest a solution should phrase it in simple words that someone of my limited teachnical ability can understand

I'm running the game on Vista and it has worked very well up until this abrupt crash. No problems at all.
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Footnote: I tried to turn off this DEP for the game by using the DEP tab in System, but, when I put kb in the list, got a message saying that kb must be run with DEP turned on. I also found on this board a recommendation to turn DEP off completely, using a command prompt, but I hesitate to do this if there's something else to try.
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Perhaps the Paladin Karastes is just not meant to marry a pirate. As I say, this is the only bug I have run into so far.