Have you tried running 4.42 on the 7200 MCP?
Are you running a SM or MMC style?
Did you upload the file(s) via IT Tool or via a card reader on laptop/pc?

The release notes we got stated that 4.46d fixed a clicking problem with 7200MCP SM style and ISDN BRI lines.

So based on that it should work.
I havn't put any of the 4.4x sw releases on a 7200MCP so can't help much more