Using: - very old Multigrade developer (it's still fully active) - slightly old but clear Kentmere VC RC paper - glacial acetic at 5% for stop - fresh Ilford Hypam at 1+4 and - a Jobo I made the first couple of prints in my new darkroom last night (yay!). However, it went suddenly from working perfectly to staining the paper tea-brown near the edges, though the silver image was still perfectly formed. One print it's perfect, next was brown and they kept coming. Narrowed it down to the developer: fixed paper came out clear, using new dev made it work again. I ran about 5 sheets (in probably 12 processes... test strips) of 8x10 in 1L of dev before it went wrong. It has an orange tinge similar to what paper gets when exposed to light but not fixed... but the paper is not in any way fogged. The staining was identical on RC and FB (bad paper was my first assumption; I tried another pack) and it extends for about 30mm from the edges (8x10s). While the dev might have been contaminated (eg something in the lift funnel), it was still working perfectly. What gives?