HI I also have the issue, but I'm using triple languages for input:
ukeyboard package for Bulgarian phonetic keyboard layout and English keyboard standard layout + mscim and mscim pinyin but after installing VKB not working anymore, till now I did not find real solution for may case.

Switching betwееn the languages Eнglish/Bulgarian I use 'Sym/Ctr'+'Space' and switching form English to MSCIM 'Sym/Ctr'+'Shift', and from MSCIM to English - using on-screen MSCIM and choose English layout.
It's complicated but these is the only way of input in these tree languages.

Also MSCIM mscim-n900-ppinputmethod (<= penpower) is really good for handwriting recognition for Chinese and English.

I also notice a noticeable performance slowdown when MSCIM is installed.

The VKB comes back only if I
and after reboot.

I'm also eager to find the solution for this problem.

You can look here, and post the same question to developers of MSCIM.

Will keep an eye on this, if someone share some possible solution?

Greetings

Martin