i have completed about 15 tasks from yoyo@home. (i dont see them complete, but i'll have 2 at say 80%, and ill come back later and they'll be gone and i'll have 2 more at 4%.)
When i go to yoyo@home, it shows i have no pending credit, and i have not received any credit in the last week.

anyone know whats going on?

Currently only one of your computers has any tasks attached to.
Both were "Aborted by user" today at 25 Oct 2010 16:26:12 UTC.

i aborted those 2 this morning, because im not getting credit, and put the project on hold,
the fact that those are the only 2 that show up is exactly what i'm talking about, there should be like 10 tasks awaiting credit.

Yoyo himself is currently abroad on a business trip in his RL-job, but I think you should post this in his forum rather than here, because it's not a stats problem.
I'll try to get him in IRC, but I think he may just be logged in and afk, not really online.

This is still going on, i let 4 computers work on yoyo tasks for 2 weeks, and no credit has been returned, and no pending tasks are shown on the site.

Again: This is nothing for a stats site but for the project admin to answer, so pleas go to the right place, i.e. yoyos forum.

You are crunching only evos, so you probably know that they don't have checkpoints and will start from scratch after every restart of the computer, and thus your computer probably runs 24/7. I don't know whether they just error out after too many restarts or not, I restart my machine once every 2-4 weeks.

oh i didnt know about the no checkpoint thing, that is exactly what has been happening im sure, because all my machines restart every 12 hours.

is there anyway to know what projects don't use checkpoints so i can stay away from them?

Yup, checkpoint is annoying sometimes... usually it's stated on the forum's project

You can mannually check if a task has it if you press "Properties" on Boinc Manager, under "CPU time at last checkpoint"; if it's marked as "--" then you have to be careful

I don't know of any english language wiki site that has such info, the unofficial wiki has some, but obviouly not complete.

In my teams Wiki it's not in the list, but in the detailed project descriptions.