Temp Monitor states "downloading" for hours, can't cancel.

[nerdkill]

HELPPPPPP. I've had this happen once before months ago and it didn't go away until the application got an update. My temp monitor app tried to update and was never able to. Now it's stuck in a "downloading" state. When I try to cancel the download I get "The application Market (process com.android.vending) has stopped unexpectedly. Please try again".

I've tried ending all processes, clearing cache, reboot. I don't know what else to do. I can't download the apk to my sd card and reinstall because it's a paid app. Any one have any ideas?