Help With SQL Query Again

So, before I asked a question regarding the below query, and it works great now. It takes the sum of each quarter sales for a each user for each year. Now, I wanted to total the 4 quarters, but it is always null, even though each sepearte quarter has a value...

Here is the query:

SELECT quotas.quotayear,lname,IsNull(q1t.tot,0) as '1st Quarter',IsNull(q2t.tot,0) as '3rd Quarter',IsNull(q3t.tot,0) as '1st Quarter',IsNull(q4t.tot,0) as '4th Quarter', q1t.tot + q2t.tot
FROM eusers
INNER JOIN quotas ON quotas.salesid = eusers.userid
LEFT OUTER JOIN (SELECT sum(tsc) as 'tot',proposal.salesid,quotas.quotayear
FROM priceinfo
INNER JOIN proposal ON proposal.sanum = priceinfo.sanum
INNER JOIN quotas on quotas.salesid = proposal.salesid
INNER JOIN quarters ON quarters.quotayear = quotas.quotayear where dajobfin between quarters.q1 AND quarters.q2
group by quotas.quotayear,proposal.salesid)
q1t ON q1t.salesid = eusers.userid and quotas.quotayear = q1t.quotayear

LEFT OUTER JOIN (SELECT sum(tsc) as 'tot',proposal.salesid,quotas.quotayear
FROM priceinfo
INNER JOIN proposal ON proposal.sanum = priceinfo.sanum
INNER JOIN quotas on quotas.salesid = proposal.salesid
INNER JOIN quarters ON quarters.quotayear = quotas.quotayear where dajobfin between quarters.q2 AND quarters.q3
group by quotas.quotayear,proposal.salesid)
q2t ON q2t.salesid = eusers.userid and quotas.quotayear = q2t.quotayear

LEFT OUTER JOIN (SELECT sum(tsc) as 'tot',proposal.salesid,quotas.quotayear
FROM priceinfo
INNER JOIN proposal ON proposal.sanum = priceinfo.sanum
INNER JOIN quotas on quotas.salesid = proposal.salesid
INNER JOIN quarters ON quarters.quotayear = quotas.quotayear where dajobfin between quarters.q3 AND quarters.q4
group by quotas.quotayear,proposal.salesid)
q3t ON q3t.salesid = eusers.userid and quotas.quotayear = q3t.quotayear

LEFT OUTER JOIN (SELECT sum(tsc) as 'tot',proposal.salesid,quotas.quotayear
FROM priceinfo
INNER JOIN proposal ON proposal.sanum = priceinfo.sanum
INNER JOIN quotas on quotas.salesid = proposal.salesid
INNER JOIN quarters ON quarters.quotayear = quotas.quotayear where dajobfin between quarters.q4 AND '1/1/2010'
group by quotas.quotayear,proposal.salesid)
q4t ON q4t.salesid = eusers.userid and quotas.quotayear = q4t.quotayear

Results look like:

2009      Shepard      0.00      0.00      0.00      971754.53      NULL
2010      Shepard      1051.34      0.00      0.00      0.00      NULL
2009      Austin      0.00      0.00      0.00      37089.40      NULL
2010      Austin      0.00      0.00      0.00      0.00      NULL

argh, why?