After 3 years of being the first in and last to leave, of getting other people's work reassigned to me - P can't complete it on time, G doesn't like the user, A refuses to work on that module, etc... I finally blew last Sept.
In the span of 2 days, my boss brought me into a project 1.5 years in (she doesn't trust P to do the coding) and expected me to be up to speed and coding in a couple of days, told the functional dept that I would cover for one of their guys on vaca for three weeks and assigned me to take over a HUGE project from one of the other functional guys who wasn't getting it done. So basically I'm now doing Ps job AND supporting another department AND taking control of a large project from another department. I'm the idiot working 14 hour days while they're all leaving on time or enjoying their 3 week vaca to India.
I lost it. It's bad enough filling in the gaps in my own department but when I'm now taking on work for other departments, that's where I draw the line. I sent my boss my resignation - just could not take the inequity in the work load.
I'm still working here - my boss ended up hiring a consultant to handle the functional project and told the functional group to find their own vacation coverage. She's also monitoring workloads much closer now. I still habe an ongoing issue with having to complete other peoples work for them but I'm not working OT to do it. So speaking up helps. So does quitting.