Go CCIE Go!! - A Cisco Certified Internetwork Expert

The setup
r1—–r2——r3——r4
On the link that connects r2 to r3, each interface has different networks subnet masks (22.22.22.22/28 for r2 and 33.33.33.33/30 for r3). All other links have normal ips that are on the same network and work fine.
Requirement: all routers are to run rip. r2 and r3 must pass routing info between each other as well as you must be able to route traffic from r1 to r4 and vice-versa. ‘ip unnumbered’ cannot be used. no static / default routes of any kind can be used.
Where I’m at: All routers can see routes from each other (used the no validate-update-source to get the routes passed along….). However, r1 for example cannot route to a network on r3 because full route recursion is not happening because the next hop for r2 is 33.33.33.33 (the interface directly connected to r3) and when doing a route lookup for 33.33.33.33, there is no recursion to an interface. a static route pointing traffic destined for the netx hops of 22.22.22.22, etc. to the serial interface can fix this but i cannot use statics for this.
Any ideas would be greatly appreciated.
Joe