Your lucky to have four reviews in the time period... good for you!
2 apps in review starting 25 Sept, both rejected, fixed and resubmitted 30 Sept. 1 was rejected again 8 october, fixed and submitted again 8 october. The other never reviewed again. 14 october expedite approved. 17 october i removed them both from review to make major updates, and resubmitted.... waiting... so, ya, kidda stinks.
on a side note.... i updated 2 of my approved apps and it took about 36-48 hours to get them approved.