If you're not using jffs2 partition which I think it is, just disable it.
Would this work?
Booting my router into recovery mode and installing the latest 374.43 merlin firmware that way and wait the 40 mins it takes to get done.
Then afterwards just leave jffs2 partition disabled.
Just a random question... what is the difference in uploading firmware via firmware recovery mode and just doing it the normal way